Oled devices including structured backfill layer and planarization layer

ABSTRACT

Organic light emitting diode (OLED) devices are disclosed that include a first layer; a backfill layer having a structured first side and a second side; a planarization layer having a structured first side and a second side; and a second layer; wherein the second side of the backfill layer is coincident with and adjacent to the first layer, the second side of the planarization layer is coincident with and adjacent to the second layer, the structured first side of the backfill layer and structured first side of the planarization layer form a structured interface, the refractive index of the backfill layer is index matched to the first layer, and the refractive index of the planarization layer is index matched to the second layer.

BACKGROUND

Nanostructures and microstructures on glass substrates are used for avariety of applications in display, lighting, architecture andphotovoltaic devices. In display devices the structures can be used forlight extraction or light distribution. In lighting devices thestructures can be used for light extraction, light distribution, anddecorative effects. In photovoltaic devices the structures can be usedfor solar concentration and antireflection. Patterning or otherwiseforming nanostructures and microstructures on large glass substrates canbe difficult and not cost-effective.

Lamination transfer methods that use a structured backfill layer insidea nanostructured sacrificial template layer as a lithographic etch maskhave been disclosed. The backfill layer can be a glass-like material.However, these methods require removing the sacrificial template layerfrom the backfill layer while leaving the structured surface of thebackfill layer substantially intact. The sacrificial template layer istypically removed by a dry etching process using oxygen plasma, athermal decomposition process, or a dissolution process.

SUMMARY

Accordingly, a need exists for fabricating nanostructures andmicrostructures in a cost-effective manner on a continuous carrier filmand then using the film to transfer or otherwise impart the structuresonto glass substrates or other permanent receptor substrates.Additionally, a need exists for fabricating nanostructures andmicrostructures over a large area with high yields to meet the needs,for example, of large digital displays.

In one aspect, a transfer tape is disclosed that includes a carrier, atemplate layer having a first surface applied to the carrier and havinga second surface opposite the first surface, wherein the second surfacecomprises a non-planar structured surface, a release coating disposedupon the non-planar structured surface of the template layer, and abackfill layer disposed upon and conforming to the non-planar structuredsurface of the release coating. The template layer is capable of beingremoved from the backfill layer while leaving at least a portion of thestructured surface of the backfill layer substantially intact. Thecarrier can include a transparent polymer and the template layer caninclude a photocurable organic resin. The backfill layer can include abilayer of two different materials, one of which can be an adhesionpromotion layer. In some embodiments the backfill layer includes asilsesquioxane such as polyvinyl silsesquioxane.

In another aspect an article is provided that includes a transfer tapeas disclosed above and a receptor substrate adjacent to the backfilllayer. The receptor substrate can be flexible glass that can be suppliedon a roll. In some embodiments, the adhesion promotion layer ispatterned. In some embodiments the template layer can include astructured residual layer and a structured crosslinked pattern. In someembodiments, when a release coating disposed upon a structured side ofthe template layer and the backfill layer disposed upon the releasecoating are separated from the disclosed transfer tape, the structuredbackfill layer reflows and becomes substantially unstructured.

In another aspect, a transfer tape is disclosed that includes a carrier,a template layer having a first surface applied to the carrier andhaving a second surface opposite the first surface, wherein the secondsurface comprises a non-planar structured surface, and a patterned curedbackfill layer disposed upon the non-planar structured surface. Theprovided transfer tape can further include a crosslinked unstructuredlayer in contact with the patterned cured backfill layer and also incontact with the portion of the template layer not covered by thepatterned cured backfill layer.

In yet another aspect, a transfer tape is disclosed that includes acarrier, a template layer having a first surface applied to the carrierand having a second surface opposite the first surface, wherein thesecond surface comprises a non-planar structured surface, an unpatternedcured sacrificial backfill layer disposed upon the non-planar structuredsurface, and a receptor substrate having an interface with the backfilllayer, wherein there are bonding regions and non-bonding regions at theinterface of the backfill layer and the receptor substrate.

In this disclosure:

“actinic radiation” refers to wavelengths of radiation that cancrosslink or cure polymers and can include ultraviolet, visible, andinfrared wavelengths and can include digital exposures from rasteredlasers, thermal digital imaging, and electron beam scanning;

“adjacent” refers to layers that are in proximity to each other, usuallyin contact with each other, but may have an intervening layer betweenthem;

“AMOLED” refers to active matrix organic light-emitting diode;

“hierarchical” refers to constructions that have two or more elements ofstructure wherein at least one element has nanostructures and at leastone element has microstructures. The elements of structure can consistof one, two, three, or more levels of depth. In the disclosedhierarchical constructions nanostructures are always smaller thanmicrostructures;

“land” refers to an unstructured width of area between two adjacentseparated microstructural elements;

“LED” refers to a light-emitting diode; “microstructures” refers tostructures that range from about 0.1 μm to about 1000 μm in theirlongest dimension. In this disclosure, the ranges of nanostructures andmicrostructures necessarily overlay;

“nanostructures” refers to features that range from about 1 nm to about1000 nm in their longest dimension;

“planarization materials or layers” refer to layers of materials thatfill in irregular surfaces to produce a substantially flat surface thatmay be used as a base to build additional layered elements;

“structures” refer to features that include microstructures,nanostructures, and/or hierarchical structures; and

“vias” refer to voids, holes, or channels with zero land in thepatterned backfill layer through which conductive elements, such aselectrodes, can be placed.

The above summary is not intended to describe each disclosed embodimentor every implementation of the present disclosure. The figures and thedetailed description below more particularly exemplify illustrativeembodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

Throughout the specification reference is made to the appended drawings,where like reference numerals designate like elements, and wherein:

FIG. 1 presents a schematic of a flow diagram of a process of making andusing a disclosed structured tape that has a backfill, an adhesionpromotion layer, and no patterning.

FIG. 2 presents a schematic of a flow diagram of a process for makingand using a using a disclosed structured tape that has a backfill and apatterned adhesion promotion layer.

FIG. 3 present a schematic of a flow diagram of a process for making andusing a using a disclosed structured tape that has a backfill and apostlamination blanket photocure.

FIG. 4 presents a schematic of a flow diagram of a process for makingand using a using a disclosed structured tape that has a backfill and apostlamination photoexposure through a lithographic mask.

FIGS. 5 and 5A present a schematic of a flow diagram of a process formaking and using a using a disclosed structured tape that has a backfilland postlamination photoexposure using direct write digital exposure.

FIG. 6 presents a schematic of a flow diagram of a process for makingand using a using a disclosed structured tape that has a backfill, apatterned prelamination photoexposure, and an vinyl silsesquioxaneovercoat.

FIGS. 7 and 7A presents a schematic of a flow diagram of a process formaking and using a using a disclosed structured tape that has a backfilland a patterned prelamination photoexposure with oxygen surfaceinhibition.

FIG. 8 presents a schematic of a flow diagram of a process for makingand using a using a disclosed structured tape that has a backfill, apatterned prelamination photoexposure, and a postlaminationphotoexposure.

FIGS. 9 and 10 present a flow diagrams of processes for making and usinga using a disclosed structured tape that has an embedded backfill with ahigh index of refraction (FIG. 9) and a low index of refraction (FIG.10).

FIGS. 11a-11b are illustrations that show that the order ofphotoexposure and lamination are important and can alter the productconstruction.

FIG. 12 is a photomicrograph of nanostructures on glass from Example 1.

FIG. 13 is a photomicrograph of patterned nanostructures on glass fromExample 7.

FIG. 14 is a photomicrograph of patterned nanostructures on glass fromExample 8.

FIG. 15 is a photomicrograph of patterned nanostructures on glass havingvias from Example 9.

FIG. 16 is a photomicrograph of patterned nanostructures on glass fromExample 11.

The figures are not necessarily to scale. Like numbers used in thefigures refer to like components. However, it will be understood thatthe use of a number to refer to a component in a given figure is notintended to limit the component in another figure labeled with the samenumber.

DETAILED DESCRIPTION

In the following description, reference is made to the accompanying setof drawings that form a part of the description hereof and in which areshown by way of illustration several specific embodiments. It is to beunderstood that other embodiments are contemplated and may be madewithout departing from the scope or spirit of the present invention. Thefollowing detailed description, therefore, is not to be taken in alimiting sense.

Unless otherwise indicated, all numbers expressing feature sizes,amounts, and physical properties used in the specification and claimsare to be understood as being modified in all instances by the term“about.” Accordingly, unless indicated to the contrary, the numericalparameters set forth in the foregoing specification and attached claimsare approximations that can vary depending upon the desired propertiessought to be obtained by those skilled in the art utilizing theteachings disclosed herein. The use of numerical ranges by endpointsincludes all numbers within that range (e.g. 1 to 5 includes 1, 1.5, 2,2.75, 3, 3.80, 4, and 5) and any range within that range.

Structured lamination transfer films and methods are disclosed thatenable the fabrication of structured solid surfaces using lamination.The methods involve replication of a film, layer, or coating in order toform a structured template layer. The replication can be performedagainst a master using any microreplication techniques known to those ofordinary skill in the art of microreplication. These techniques caninclude, for example, embossing, cast and cure of a prepolymer resin(using thermal or photochemical initiation), or hot melt extrusion.Typically microreplication involves casting of a photocurable prepolymersolution against a template followed by photopolymerization of theprepolymer solution. In this disclosure, “nanostructured” refers tostructures that have features that are less than 1 μm, less than 750 nm,less than 500 nm, less than 250 nm, 100 nm, less than 50 nm, less than10 nm, or even less than 5 nm. “Microstructured” refers to structuresthat have features that are less than 1000 μm, less than 100 μm, lessthan 50 μm, or even less than 5 μm. Hierarchical refers to structureswith more than one size scale include microstructures withnanostructures (e.g. a microlens with nanoscale moth eye antireflectionfeatures). Lamination transfer films have been disclosed, for example,in Applicants' pending unpublished application, U.S. patent applicationSer. No. 13/553,987, entitled “STRUCTURED LAMINATION TRANSFER FILMS ANDMETHODS”, filed Jul. 20, 2012.

In some embodiments, a photocurable prepolymer solution, typicallyphotocurable upon exposure to actinic radiation (typically ultravioletradiation) can be cast against a microreplicated master and then exposedto actinic radiation while in contact with the microreplicated master toform the template layer. The photocurable prepolymer solution can becast onto a carrier film before, during, and even sometimes after, beingphotopolymerized while in contact with a microreplicated master. Thecarrier film having the cured microreplicated template layer disposedupon it can be used to produce disclosed patterned structured transfertapes.

Disclosed patterned structured transfer tapes and methods of making themas well as structures produced by processes utilizing these transfertapes are illustrated by referencing the figures. FIG. 1 presents a flowdiagram of a process of making and using a disclosed structured tapethat uses a backfill, an adhesion promotion layer, and no patterning.Structured template layer 103 is disposed upon carrier 101. Structuredtemplate layer 103 has a thin layer of release coating (not shown)deposited by, in some cases, plasma enhanced chemical vapor deposition.In some embodiments, release properties may be inherent to thestructured template layer. The resulting structure is then coated withuncured backfill layer 105 so that uncured backfill layer 105 completelycontacts structured template layer 103 (step 11). The backfill may thenbe dried, thermally crosslinked, or photocrosslinked to produce a stableintermediate film that, optionally, can be covered with release liner104 for protection. The structure is then inverted and laminated toreceptor substrate 110 coated with adhesion promotion layer 112 (step12). Adhesion promotion layer 112 is coated uniformly on receptorsubstrate 110 without patterning. After removal of release coatedstructured template layer 103 on carrier 101 (step 13), the articleincludes structured backfill layer 105 adhered to receptor substrate 110through adhesion promotion layer 112. Optionally, structured backfilllayer 105 can then be subjected to further thermal treatment, such aspyrolysis to sinter, cure, or fuse the backfill layer 105 and tovaporize any remaining organic materials.

FIG. 2 shows structured template layer 203 disposed upon carrier 201.Structured template layer 203 may have a thin layer of release coating(not shown) deposited by plasma enhanced chemical vapor deposition orother means. The resulting structure is then coated with uncuredbackfill layer 205 so that uncured backfill layer 205 completelycontacts structured template layer 203 (step 21). This stableintermediate film can, optionally, be covered with release liner 204 forprotection. The resulting structure is then inverted and laminated toreceptor substrate 210 coated with patterned adhesion promotion layer212 (step 22). Patterned adhesion promotion layer 212 is applied toreceptor substrate 210 and patterned via photolithography. After removalof release coated structured template layer 203 on carrier 201 (step23), the article includes structured uncured backfill layer 205 adheredto receptor substrate 210 through patterned adhesion promotion layer212. Where there is no patterned adhesion promotion layer 212 (betweenthe patterns) backfill layer 205 adheres to structured template layer203 and is removed leaving a via or open region. This structure with avia (area without backfill) can be important in active matrix organiclight emitting diode (AMOLED) extraction applications where the removedarea corresponds to regions requiring a via on the AMOLED backplane(e.g. the electrical connection between a subpixel circuit and acorresponding subpixel electrode). Additionally, the presented methodallows for precision alignment between the vias and fiducials or otherfeatures on the substrate surface that can be on a receptor substrate.

In some embodiments, backfills are tacky at room temperature beforephotocuring. For example, polyvinyl silsesquioxane as a backfill can beused in disclosed patterned structured transfer tapes without anadhesion promotion layer. FIG. 3 shows structured template layer 303disposed upon carrier 301. The resulting structure is then coated withuncured backfill layer 305 (step 31). Uncured backfill layer 305contacts structured template layer 303. A stable intermediate film isproduced by laminating of temporary liner 304 to the uncured backfilllayer. The liner is removed prior to use of the lamination transferfilm. Once the liner is removed, the assembly is then inverted andlaminated to receptor substrate 310 without adhesion promotion layer 212when uncured backfill layer 305 is vinyl silsesquioxane (step 32). Thestructure is then exposed to blanket ultraviolet radiation 320 to curestructured backfill layer 305 (step 33) and to promote better adhesionto receptor substrate 310. Alternatively, heat may be used to cure thebackfill layer. After removal of release coated structured templatelayer 303 on carrier 301, the article includes structured cured backfilllayer 306 disposed upon receptor substrate 310. Optionally, structuredcured backfill 306 can then be subjected to further thermal treatment,such as pyrolysis to sinter, cure, or fuse the backfill layer 305 and tovaporize any remaining organic materials.

Uncured backfill layers can reflow upon template release. An exemplarybackfill material that can reflow upon template release is vinylsilsesquioxane. In some embodiments, heat may be employed to enable thereflow of some uncured backfill materials. Patterned and unpatternedareas (due to reflow) can be defined by photocuring through a patternedmask. After removal from the template, the uncured areas of the backflowcan reflow to form planarized surfaces, and then a final blanket curecan be used to polymerize the remainder of the uncured areas. FIG. 4shows structured template layer 403 disposed upon carrier 401.Structured template layer 403 has a thin layer of release coating (notshown) deposited by plasma enhanced chemical vapor deposition. Theresulting structure is then coated with uncured backfill layer 405 sothat uncured backfill layer 405 completely contacts structured templatelayer 403 (step 41). A stable intermediate film is produced bylaminating temporary liner 404 to the uncured backfill layer. The lineris removed prior to use of the lamination transfer film. Once the lineris removed, the assembly is then inverted and laminated to receptorsubstrate 410 (step 42). The structure is exposed to first actinicradiation 420 through photomask 425 disposed upon photomask carrier 424.First actinic radiation 420 photopolymerizes backfill 406 where it isnot blocked by photomask 425. First actinic radiation 420 cannotpenetrate beyond photomask 425 so that backfill layer 405 remainsunpolymerized. After removal of release coated structured template layer403 on carrier 401, the article includes structured cured backfill layer406 adhered to receptor substrate 410 (step 43). Uncured backfill layer405 reflows and becomes substantially planarized (unstructured) 407after removal from contact with template layer. After reflow, photomask425 is removed and the structure is exposed to blanket actinicradiation, 422, to fully cure the backfill (step 44). Optionally, thisstructure can then be subjected to further thermal treatment, such aspyrolysis to sinter, cure, or fuse the backfill layer 405 and tovaporize any remaining organic materials.

In some embodiments, a digital laser exposure can be used to polymerizeselective portions of the backfill layer. FIG. 5 presents a flow diagramof a process for making and using a disclosed structured tape that usesa curable backfill and postlamination first photoexposure using directwrite digital laser exposure. FIG. 5 shows structured template layer 503disposed upon carrier 501. Structured template layer 503 has a thinlayer of release coating (not shown) deposited by plasma enhancedchemical vapor deposition or some other means using known coatingmethods. The resulting structure is then coated with uncured backfilllayer 505 so that uncured backfill layer 505 contacts structuredtemplate layer 503 (step 51). A stable intermediate film is producedthat, optionally, can be laminated with temporary liner 504 for storageand further handling. The liner is removed prior to use of thelamination transfer film. The structure is then inverted and laminatedto receptor substrate 510 (step 52). The resulting structure is exposedto a rastered or vector-scanned beam of radiation from first directwrite digital laser 520. First direct write digital laser 520photopolymerizes backfill 506 in the areas exposed to the laser beam.Areas of backfill layer 505 that have not been exposed to the laser beamremain unpolymerized. After removal of release coated structuredtemplate layer 503 on carrier 501 (step 53), the article includesstructured cured backfill layer 506 adhered to receptor substrate 510.Uncured backfill layer 505 reflows and becomes substantially planarized(unstructured) 507 after removal from contact with template layer. Afterreflow the structure is exposed to a second actinic radiation 522 tofully cure the backfill 508 (step 54). FIG. 5A illustrates a smallvolume element showing laser exposed area 523 being polymerized by abeam from first direct write digital laser 520. Optionally, thisstructure can then be subjected to further thermal treatment, such aspyrolysis to sinter, cure, or fuse the backfill layer 505 and tovaporize any remaining organic materials.

FIG. 6 illustrates a method to manufacture a pre-exposed patternedlamination transfer film. This method may be important for architecturalapplications such as bird avoidance films and graded daylightredirecting films. Pre-exposed patterned lamination transfer films maybe useful in applications in which precise positioning (e.g. alignmentto fiducials on a receptor substrate) is not required. FIG. 6 presents aflow diagram of a process for making and using a disclosed structuredtape that uses a backfill, a pre-lamination patterned photoexposure, andan adhesion promotion layer. FIG. 6 shows structured template layer 603disposed upon carrier 601. Structured template layer 603 has a thinlayer of release coating (not shown) deposited by plasma enhancedchemical vapor deposition. Alternatively, other method of surfacemodification or coatings may be used to enhance the release propertiesof the structured template layer. The resulting structure is then coatedwith uncured backfill layer 605 (vinyl silsesquioxane) so that uncuredbackfill layer 605 completely contacts structured template layer 603(step 61) and forms a stable intermediate film that can, optionally, becovered with release liner 604 for protection during handling. Thestructure is exposed to first actinic radiation 620 through photomask625 disposed upon photomask carrier 624 (step 62). First actinicradiation 620 photopolymerizes backfill 606 where it is not blocked byphotomask 625. First actinic radiation 620 cannot penetrate beyondphotomask 625 so that backfill 605 remains unpolymerized. The resultingstructure after first actinic radiation exposure is then overcoated withadhesion promotion layer 609 which, in some embodiments, can be the samematerial as backfill 605 (step 63). A stable intermediate film is formedthat, optionally, can be covered with temporary liner 604 for storageand future handling. The resulting structure is then inverted andlaminated to receptor substrate 610 (step 64). Carrier 601 with releasecoated template layer 603 is then removed (step 65). Structured andcured backfill 606 then remains structured only in areas that have beenexposed to actinic radiation. Unexposed backfill 607 reflows to formareas with unstructured surfaces. The reflow process can occur at roomtemperature or can be assisted by heat. Finally, the backfill layers(structured and unstructured) as cured by second blanket actinicexposure 622 (step 66). Optionally, this structure can then be subjectedto further thermal treatment, such as pyrolysis to sinter, cure, or fusebackfill layer 605 and to vaporize any remaining organic materials.

FIG. 7 presents a flow diagram of a process for making and using adisclosed structured tape that uses a backfill and a prelaminationphotoexposure with oxygen surface inhibition. Inhibiting the surfacecure of the backfill layer allows direct lamination to the receptorsubstrate without need for an adhesion promotion layer as is required inthe process illustrated in FIG. 1 or an overcoat as in the processillustrated in FIG. 6. FIG. 7 shows structured template layer 703disposed upon carrier 701. Structured template layer 703 has a thinlayer of release coating (not shown) deposited by plasma enhancedchemical vapor deposition. The resulting structure is then coated withuncured backfill layer 705 so that uncured backfill layer 705 completelycontacts structured template layer 703 (step 71). The structure isexposed to first actinic radiation 720 through photomask 725 disposedupon photomask carrier 724 with the top surface of backfill layer 705exposed to oxygen to inhibit surface curing (step 72). The oxygeninhibits curing at the surface of the backfill layer and produces agradient of cure from the surface inwards through the bulk of thebackfill layer. First actinic radiation 720 photopolymerizes backfill706 where it is not blocked by photomask 725. First actinic radiation720 cannot penetrate beyond photomask 725 so that backfill layer 705remains unpolymerized. The entire air interface of the backfill layer705/706, remains tacky due to the surface inhibition of curing.Optionally, after curing, the backfill can be covered with temporaryrelease liner 704 for protection during handling (step 73). Theresulting structure, with temporary release liner removed, is theninverted and laminated to receptor substrate 710 (step 74). Carrier 701with release coated template layer 703 is then removed (step 75).Structured and cured backfill 706 then remains only in areas that havebeen exposed to actinic radiation. Unexposed backfill 707 reflows (step76) to form an unstructured area. The height of the unstructured area isless than the mean height of any structural elements in the structuredtransfer tape. Finally, the backfill layers (structured andunstructured) are cured by blanket second actinic radiation exposure 722(step 76). Optionally, this structure can then be subjected to furtherthermal treatment, such as pyrolysis to sinter, cure, or fuse thebackfill layer 705 and to vaporize any remaining organic materials.

FIG. 8 presents a flow diagram of a process for making and using adisclosed structured tape that uses a backfill and a prelaminationphotoexposure. This process can also produce vias (zero land areas) thatcan be useful, for example, in constructing OLED devices. FIG. 8 showsstructured template layer 803 disposed upon carrier 801. Structuredtemplate layer 803 has a thin layer of release coating (not shown)deposited by plasma enhanced chemical vapor deposition. The resultingstructure is then coated with uncured backfill layer 805 so that uncuredbackfill layer 805 completely contacts structured template layer 803(step 81). The structure is exposed to first actinic radiation 820through photomask 825 disposed upon photomask carrier 824 (step 82).First actinic radiation 820 photopolymerizes backfill 806 in areas thatare not blocked by photomask 825. First actinic radiation 820 cannotpenetrate beyond photomask 825 so that backfill 805 remainsunpolymerized. Patterned first actinic radiation 820 also leaves“bonding regions” 812 (from uncured backfill 805) at the receptorsubstrate interface and “non-bonding regions” 814 (from cured patternedbackfill 806) at the receptor interface. “Bonding regions” are areas inwhich the adhesive force between the receptor surface and the backfillis greater than that between the backfill and the structured template(or release layer). In “non-bonding regions”, the opposite is true. Thelocation of the “bonding regions” and “non-bonding regions” can bedetermined by the opaque and transparent features on photomask 825.Optionally, a release liner can be used to protect the exposed structureand to create a stable intermediate for storage or handling. Thestructure is then inverted and laminated to receptor substrate 810 (step83). Blanket (unpatterned) second exposure to actinic radiation 822cures all uncured area of backfill layer 805 (step 84). Release coatedstructured template layer 803 on carrier 801 can be separatedtransferring structured backfill layer 830 a to receptor substrate 810in areas of “bonding region” 814 and separating portions of backfilllayer 830 b that are over non-bonded regions 812 (step 85). The resultis that patterned, structured backfill layer 830 a has been transferredto receptor substrate 810. The separated structure containing a via canthen, optionally, subjected to further thermal treatment, such aspyrolysis to sinter, cure, or fuse the backfill layer 105 and tovaporize any remaining organic materials.

FIGS. 9 and 10 present flow diagrams of processes for making and using adisclosed structured tape that includes a dyad of two transfer layerswith refractive indices n₁ and n₂, where n₂>n₁ and an interlayerinterface comprising a micro-, nano- or hierarchical structure. Oneprocess can be used to fabricate a dyad on a receptor surface in whichthe lower refractive index layer is embedded between the receptor andthe outer transfer layer (FIG. 9). Another process can be used tofabricate a dyad on a receptor surface in which the higher refractiveindex layer is embedded (FIG. 10). FIG. 9 illustrates a method formaking an embedded structure with a first dyad layer having an index ofrefraction n˜1.5 or greater, typically around 1.55 and a second dyadlayer, with n˜1.8, adjacent to the first dyad layer, so that theembedded structure, when transferred to a receptor substrate such asglass (n˜1.5) has a similar index of refraction to that of the receptorsubstrate. In this configuration the dyad can serve as an extractioninterface between the receptor substrate (glass) and a transparentconductor such as indium-tin-oxide (n around 1.8). During theillustrated process a dyad of layers (structured template layer andstructured backfill layer) is transferred to a receptor substrate as asingle unit. The process illustrated in FIG. 9 can be combined withpatterning methods previously illustrated (see, for example, FIG. 8 thatcan create vias on an AMOLED backplane). FIG. 9 shows structuredtemplate layer 903 disposed upon carrier 901. Structured template layer903 has a higher index of refraction (typically n≧1.55, and moretypically around 1.8). The structure is then coated with uncuredbackfill layer 905 having a lower index of refraction (less than theindex of refraction of structured template layer 903 and typicallyn≦1.55) (step 91). Uncured backfill layer 905 completely contactsstructured template layer 903. Optionally, the backfill can be coveredwith release liner 904 for protection during handling. The structure isthen inverted and laminated to receptor substrate 910 without anadhesion promotion layer when uncured backfill layer is tacky beforecure (step 92). The structure is then exposed to blanket actinicradiation 920 to cure structured backfill layer 905 to give thestructure (step 93). After removal of carrier 901, an article isobtained that includes structured cured backfill layer 905 having alower index of refraction disposed upon structured template layer havinga higher index of refraction in contact with receptor substrate 910(step 94).

FIG. 10 illustrates a method for making an embedded structure with ahigher index of refraction n≧1.5, typically around 1.8. The processillustrated in these figures can be useful for embedded diffractive orrefractive optical elements as well as decorative surface effects onhigh index glass or crystal. Embedding the optical structure in thismanner improves the durability and of the element and protects it fromcontamination with dirt, dust, debris, or skin oil. During theillustrated process a dyad of layers (structured template layer andstructured backfill layer) is transferred to a receptor substrate. Theprocess illustrated in FIG. 10 can be combined with patterning methodspreviously illustrated (see, for example, FIG. 8 that can create vias onan AMOLED backplane). FIG. 10 shows structured template layer 1003disposed upon carrier 1001. Structured template layer 1003 has arelatively low index of refraction compared with the backfill layer. Theresulting structure is then coated with uncured backfill layer 1005having a high index of refraction (higher than the index of refractionof structured template layer 1003 and typically n≦1.5) (step 95).Uncured backfill layer 1005 completely contacts structured templatelayer 1003. Optionally, the backfill can be covered with release liner1004 for protection during handling. The structure is then inverted andlaminated to receptor substrate 1010 without an adhesion promotion layerwhen uncured backfill layer is tacky before cure (step 96). Thestructure is then exposed to actinic radiation or thermal 1020 to curethe structured backfill layer 1005 (step 97). After removal of carrier1001, an article is obtained that includes structured cured backfilllayer 1005 having a high index of refraction disposed upon structuredtemplate layer having a high index of refraction in contact withreceptor substrate 1010 (step 98).

The transfer films shown in FIGS. 1-10 can be used to transfernanostructures onto receptor substrates such as active matrix OLED(AMOLED) backplanes, AMOLED color filters on array substrates, or OLEDsolid state lighting element substrates. These nanostructures canenhance light extraction from the OLED devices, alter the lightdistribution pattern, improve the angular color uniformity of thedevices, or some combination thereof.

FIG. 11 is an illustration that shows that the order of photoexposureand steps can determine the result of the lamination transfer resultingin a great degree of control over the process. The upper scheme in FIG.11 generally follows the process presented in FIG. 8. Exposure toactinic radiation, then lamination, results in a patterned area with avia in the exposed region. Reversing the steps, the lower scheme in FIG.11 leads to lamination transfer over the entire area with patterning inthe exposed regions only, and generally follows the process presented inFIG. 4. The result can be controlled and can yield one structure withactinic patterned curing then lamination (FIG. 11a ) or a differentstructure with lamination followed by patterned curing with actinicradiation. (FIG. 11b ).

Applications of Lamination Transfer Films

The lamination transfer films disclosed herein can be used for a varietyof purposes. For example, the lamination transfer films can be used totransfer structured layers in OLED devices as disclosed above.

Another exemplary application of the lamination transfer films is forpatterning of digital optical elements including microfresnel lenses,diffractive optical elements, holographic optical elements, and otherdigital optics disclosed in Chapter 2 of B. C. Kress, and P. Meyrueis,Applied Digital Optics, Wiley, 2009, on either the internal or externalsurfaces of display glass, photovoltaic glass elements, LED wafers,silicon wafers, sapphire wafers, architectural glass, metal, nonwovens,paper, or other substrates.

The lamination transfer films can also be used to produce decorativeeffects on glass surfaces. For example, it might be desirable to impartiridescence to the surface of a decorative crystal facet. In particular,the glass structures can be used in either functional or decorativeapplications such as transportation glasses, architectural glasses,glass tableware, artwork, display signage, and jewelry or otheraccessories. Durability of the glass structures may be improved by usingthe methods disclosed herein to transfer embedded structures. Also, acoating can be applied over these glass structures. This optionalcoating can be relatively thin in order to avoid adversely affecting theglass structure properties. Examples of such coatings includehydrophilic coatings, hydrophobic coatings, protective coatings,anti-reflection coatings and the like.

Materials

Six main classes of materials are required for the fabrication of thestructured transfer films for the patterning of solid optical surfaces:carrier films, receptor substrates, template layer, release layer,backfill and planarization materials of tunable refractive index, andliners to protect the backfill layer after manufacture beforelamination.

Carrier Films

The liner or carrier substrate can be implemented with a flexible filmproviding mechanical support for the other layers. One example of acarrier film is polyethylene terephthalate (PET). In some embodiments,the carrier can include paper, release-coated paper, non-wovens, wovens(fabric), metal films, and metal foils.

Various polymeric film substrates comprised of various thermosetting orthermoplastic polymers are suitable for use as the carrier. The carriermay be a single layer or multi-layer film. Illustrative examples ofpolymers that may be employed as the carrier layer film include (1)fluorinated polymers such as poly(chlorotrifluoroethylene),poly(tetrafluoroethylene-cohexafluoropropylene),poly(tetrafluoroethylene-co-perfluoro(alkyl)vinylether), poly(vinylidenefluoride-cohexafluoropropylene); (2) ionomeric ethylene copolymerspoly(ethylene-co-methacrylic acid) with sodium or zinc ions such asSURLYN-8920 Brand and SURLYN-9910 Brand available from E. I. duPontNemours, Wilmington, Del.; (3) low density polyethylenes such as lowdensity polyethylene; linear low density polyethylene; and very lowdensity polyethylene; plasticized vinyl halide polymers such asplasticized poly(vinylchloride); (4) polyethylene copolymers includingacid functional polymers such as poly(ethylene-co-acrylic acid) “EAA”,poly(ethylene-co-methacrylic acid) “EMA”, poly(ethylene-co-maleic acid),and poly(ethylene-co-fumaric acid); acrylic functional polymers such aspoly(ethylene-co-alkylacrylates) where the alkyl group is methyl, ethyl,propyl, butyl, et cetera, or CH3 (CH2)n- where n is 0 to 12, andpoly(ethylene-co-vinylacetate) “EVA”; and (5) (e.g.) aliphaticpolyurethanes. The carrier layer is typically an olefinic polymericmaterial, typically comprising at least 50 wt-% of an alkylene having 2to 8 carbon atoms with ethylene and propylene being most commonlyemployed. Other body layers include for example poly(ethylenenaphthalate), polycarbonate, poly(meth)acrylate (e.g., polymethylmethacrylate or “PMMA”), polyolefins (e.g., polypropylene or “PP”),polyesters (e.g., polyethylene terephthalate or “PET”), polyamides,polyimides, phenolic resins, cellulose diacetate, cellulose triacetate(TAC), polystyrene, styrene-acrylonitrile copolymers, cyclic olefincopolymers, epoxies, and the like.

Receptor Substrates

Examples of receptor substrates include glass such as display motherglass, lighting mother glass, architectural glass, plate glass, rollglass, and flexible glass (can be used in roll to roll processes). Anexample of flexible roll glass is the WILLOW glass product from CorningIncorporated. Other examples of receptor substrates includes metals suchas metal sheets and foils. Yet other examples of receptor substratesinclude sapphire, silicon, silica, and silicon carbide. Yet anotherexample includes fabric, nonwovens, and papers.

Other exemplary receptor substrates include semiconductor materials on asupport wafer. The dimensions of these receptor substrates can exceedthose of a semiconductor wafer master template. Currently, the largestwafers in production have a diameter of 300 mm. Lamination transferfilms produced using the method disclosed herein can be made with alateral dimension of greater than 1000 mm and a roll length of hundredsof meters. In some embodiments, the receptor substrates can havedimensions of about 620 mm×about 750 mm, of about 680 mm×about 880 mm,of about 1100 mm×about 1300 mm, of about 1300 mm×about 1500 mm, of about1500 mm×about 1850 mm, of about 1950 mm×about 2250 mm, or about 2200mm×about 2500 mm, or even larger. For long roll lengths, the lateraldimensions can be greater than about 750 mm, greater than about 880 mm,greater than about 1300 mm, greater than about 1500 mm, greater thanabout 1850 mm, greater than about 2250 nm, or even greater than about2500 mm. Typical dimensions have a maximum patterned width of about 1400mm and a minimum width of about 300 mm. The large dimensions arepossible by using a combination of roll-to-roll processing and acylindrical master template. Films with these dimensions can be used toimpart nanostructures over entire large digital displays (e.g., a 55inch diagonal display, with dimensions of 52 inches wide by 31.4 inchestall).

The receptor substrate can optionally include a buffer layer on a sideof the receptor substrate to which a lamination transfer film isapplied. Examples of buffer layers are disclosed in U.S. Pat. No.6,396,079 (Hayashi et al.), which is incorporated herein by reference asif fully set forth. One type of buffer layer is a thin layer of SiO₂, asdisclosed in K. Kondoh et al., J. of Non-Crystalline Solids 178 (1994)189-98 and T-K. Kim et al., Mat. Res. Soc. Symp. Proc. Vol. 448 (1997)419-23.

A particular advantage of the transfer process disclosed herein is theability to impart structure to receptor surfaces with large surfaces,such as display mother glass or architectural glass. The dimensions ofthese receptor substrates exceed those of a semiconductor wafer mastertemplate. The large dimensions of the lamination transfer films arepossible by using a combination of roll-to-roll processing and acylindrical master template.

An additional advantage of the transfer process disclosed herein is theability to impart structure to receptor surface that are not planar. Thereceptor substrate can be curved, bent twisted, or have concave orconvex features, due to the flexible format of the transfer tape.

Receptor substrates also may include, automotive glass, sheet glass,flexible electronic substrates such as circuitized flexible film,display backplanes, solar glass, metal, polymers, polymer composites,and fiberglass.

Template Layer

The template layer is the layer that imparts the structure to thebackfill layer. It is made up of template materials. The template layercan be formed through embossing, replication processes, extrusion,casting, or surface structuring, for example. The structured surface caninclude nanostructures, microstructures, or hierarchical structures.Nanostructures comprise features having at least one dimension (e.g.,height, width, or length) less than or equal to one micron.Microstructures comprise features having at least one dimension (e.g.,height, width, or length) less than or equal to one millimeter.Hierarchical structures are combinations of nanostructures andmicrostructures. In some embodiments, the template layer can becompatible with patterning, actinic patterning, embossing, extruding,and coextruding.

Typically, the template layer includes a photocurable material that canhave a low viscosity during the replication process and then can bequickly cured to form a permanent crosslinked polymeric network “lockingin” the replicated nanostructures, microstructures or hierarchicalstructures. Any photocurable resins known to those of ordinary skill inthe art of photopolymerization can be used for the template layer. Theresin used for the template layer must be capable, when crosslinked, ofreleasing from the backfill layer during the use of the disclosedstructured tapes, or should be compatible with application of a releaselayer (see below) and the process for applying the release layer.Additionally, the resins used for the template layer must be compatiblewith the application of an adhesion promotion layer as discussed above.

Polymers that can be used as the template layer also include thefollowing: styrene acrylonitrile copolymers; styrene(meth)acrylatecopolymers; polymethylmethacrylate; polycarbonate; styrene maleicanhydride copolymers; nucleated semi-crystalline polyesters; copolymersof polyethylenenaphthalate; polyimides; polyimide copolymers;polyetherimide; polystyrenes; syndiodactic polystyrene; polyphenyleneoxides; cyclic olefin polymers; and copolymers of acrylonitrile,butadiene, and styrene. One preferable polymer is the Lustran SANSparkle material available from Ineos ABS (USA) Corporation. Polymersfor radiation cured template layers include cross linked acrylates suchas multifunctional acrylates or epoxies and acrylated urethanes blendedwith mono- and multifunctional monomers.

Patterned structured template layers can be formed by depositing a layerof a radiation curable composition onto one surface of a radiationtransmissive carrier to provide a layer having an exposed surface,contacting a master with a preformed surface bearing a pattern capableof imparting a three-dimensional microstructure of precisely shaped andlocated interactive functional discontinuities including distal surfaceportions and adjacent depressed surface portions into the exposedsurface of the layer of radiation curable composition on said carrierunder sufficient contact pressure to impart said pattern into saidlayer, exposing said curable composition to a sufficient level ofradiation through the carrier to cure said composition while the layerof radiation curable composition is in contact with the patternedsurface of the master. This cast and cure process can be done in acontinuous manner using a roll of carrier, depositing a layer of curablematerial onto the carrier, laminating the curable material against amaster and curing the curable material using actinic radiation. Theresulting roll of carrier with a patterned, structured template disposedthereon can then be rolled up. This method is disclosed, for example, inU.S. Pat. No. 6,858,253 (Williams et al.).

For extrusion or embossed template layers, the materials making up thetemplate layer can be selected depending on the particular topography ofthe top structured surface that is to be imparted. In general, thematerials are selected such that the structure is fully replicatedbefore the materials solidify. This will depend in part on thetemperature at which the material is held during the extrusion processand the temperature of the tool used to impart the top structuredsurface, as well as on the speed at which extrusion is being carriedout. Typically, the extrudable polymer used in the top layer has a T_(g)of less than about 140° C., or a T_(g) of from about 85° C. to about120° C., in order to be amenable to extrusion replication and embossingunder most operating conditions. In some embodiments, the carrier filmand the template layer can be coextruded at the same time. Thisembodiment requires at least two layers of coextrusion—a top layer withone polymer and a bottom layer with another polymer. If the top layercomprises a first extrudable polymer, then the first extrudable polymercan have a T_(g) of less than about 140° C. or a T_(g) or of from about85° C. to about 120° C. If the top layer comprises a second extrudablepolymer, then the second extrudable polymer, which can function as thecarrier layer, has a T_(g) of less than about 140° C. or a T_(g) of fromabout 85° C. to about 120° C. Other properties such as molecular weightand melt viscosity should also be considered and will depend upon theparticular polymer or polymers used. The materials used in the templatelayer should also be selected so that they provide good adhesion to thecarrier so that delamination of the two layers is minimized during thelifetime of the optical article.

The extruded or coextruded template layer can be cast onto a master rollthat can impart patterned structure to the template layer. This can bedone batchwise or in a continuous roll-to-roll process. Additionally, abackfill layer can be extruded onto the extruded or coextruded templatelayer. In some embodiments, all three layers—carrier, template, andbackfill layers can be coextruded at once as long as the backfill layercan be separated from the template layer after processing.

Useful polymers that may be used as the template layer polymer includeone or more polymers selected from the group consisting of styreneacrylonitrile copolymers; styrene(meth)acrylate copolymers;polymethylmethacrylate; styrene maleic anhydride copolymers; nucleatedsemi-crystalline polyesters; copolymers of polyethylenenaphthalate;polyimides; polyimide copolymers; polyetherimide; polystyrenes;syndiodactic polystyrene; polyphenylene oxides; and copolymers ofacrylonitrile, butadiene, and styrene. Particularly useful polymers thatmay be used as the first extrudable polymer include styreneacrylonitrile copolymers known as TYRIL copolymers available from DowChemical; examples include TYRIL 880 and 125. Other particularly usefulpolymers that may be used as the template polymer include styrene maleicanhydride copolymer DYLARK 332 and styrene acrylate copolymer NAS 30,both from Nova Chemical. Also useful are polyethylene terephthalateblended with nucleating agents such as magnesium silicate, sodiumacetate, or methylenebis(2,4-di-t-butylphenol) acid sodium phosphate.

Exemplary polymers with high refractive indices useful as the top skinlayer include CoPENs (copolymers of polyethylenenaphthalate), CoPVN(copolymers of polyvinylnaphthalene) and polyimides includingpolyetherimide. Suitable resin compositions include transparentmaterials that are dimensionally stable, durable, weatherable, andreadily formable into the desired configuration. Examples of suitablematerials include acrylics, which have an index of refraction of about1.5, such as PLEXIGLAS brand resin manufactured by Rohm and HaasCompany; polycarbonates, which have an index of refraction of about1.59; reactive materials such as thermoset acrylates and epoxyacrylates; polyethylene based ionomers, such as those marketed under thebrand name of SURLYN by E. I. Dupont de Nemours and Co., Inc.;(poly)ethylene-co-acrylic acid; polyesters; polyurethanes; and celluloseacetate butyrates. The template layer may be prepared by castingdirectly onto a carrier film, such as disclosed in U.S. Pat. No.5,691,846 (Benson). Polymers for radiation cured structures includecross linked acrylates such as multifunctional acrylates or epoxies andacrylated urethanes blended with mono- and multifunctional monomers.

The template layer may be sacrificial meaning that it will be removedfrom the construction at a later time as is the template layer disclosedin Applicants' pending unpublished application, U.S. patent applicationSer. No. 13/553,987, entitled “STRUCTURED LAMINATION TRANSFER FILMS ANDMETHODS”, filed Jul. 20, 2012. However, the method for making thedisclosed transfer tapes and articles made therefrom do not require thatthe template layer be sacrificial.

Release Layer

The template layer must be removed from the backfill layer. One methodto reduce the adhesion of the backfill layer to the template layer is toapply a release coating to the film. One method of applying a releasecoating to the surface of the template layer is with plasma deposition.An oligomer can be used to create a plasma cross-linked release coating.The oligomer may be in liquid or in solid form prior to coating.Typically the oligomer has a molecular weight greater than 1000. Also,the oligomer typically has a molecular weight less than 10,000 so thatthe oligomer is not too volatile. An oligomer with a molecular weightgreater than 10,000 typically may be too non-volatile, causing dropletsto form during coating. In one embodiment, the oligomer has a molecularweight greater than 3000 and less than 7000. In another embodiment, theoligomer has a molecular weight greater than 3500 and less than 5500.Typically, the oligomer has the properties of providing a low-frictionsurface coating. Suitable oligomers include silicone-containinghydrocarbons, reactive silicone containing trialkoxysilanes, aromaticand aliphatic hydrocarbons, fluorochemicals and combinations thereof.For examples, suitable resins include, but are not limited to,dimethylsilicone, hydrocarbon based polyether, fluorochemical polyether,ethylene tetrafluoroethylene, and fluorosilicones. Fluorosilane surfacechemistry, vacuum deposition, and surface fluorination may also be usedto provide a release coating.

Plasma polymerized thin films constitute a separate class of materialfrom conventional polymers. In plasma polymers, the polymerization israndom, the degree of cross-linking is extremely high, and the resultingpolymer film is very different from the corresponding “conventional”polymer film. Thus, plasma polymers are considered by those skilled inthe art to be a uniquely different class of materials and are useful inthe disclosed articles.

In addition, there are other ways to apply release coatings to thetemplate layer, including, but not limited to, blooming, coating,coextrusion, spray coating, electrocoating, or dip coating.

Backfill and Planarization Materials

The backfill layer is a material capable of substantially planarizingthe adjacent layer (e.g., the template layer) while also conforming tothe surface of the receptor layer. The backfill layer can alternativelybe a bilayer of two different materials where the bilayer has amulti-layer structure or where one of the materials is at leastpartially embedded in the other material. The two materials for thebilayer can optionally have different indices of refraction. One of thebilayers can optionally comprise an adhesion promoting layer.

Substantial planarization means that the amount of planarization (P %),as defined by Equation (1), is preferably greater than 50%, morepreferably greater than 75%, and most preferably greater than 90%.

P %=(1−(t ₁ /h ₁))*100   Equation (1)

where t₁ is the relief height of a surface layer and h₁ is the featureheight of features covered by the surface layer, as further disclosed inP. Chiniwalla, IEEE Trans. Adv. Packaging 24(1), 2001, 41.

Materials that may be used for the backfill include polysiloxane resins,polysilazanes, polyimides, silsesquioxanes of bridge or ladder-type,silicones, and silicone hybrid materials and many others. Exemplarypolysiloxane resins include PERMANEW 6000 L510-1, available fromCalifornia Hardcoat, Chula Vista, Calif. These molecules typically havean inorganic core which leads to high dimensional stability, mechanicalstrength, and chemical resistance, and an organic shell that helps withsolubility and reactivity. There are many commercial sources of thesematerials, which are summarized in Table 2 below. Other classes ofmaterials that may be of use are benzocyclobutenes, soluble polyimides,and polysilazane resins, for example.

Materials useful for the backfill layer can include vinylsilsesquioxanes; sol gel materials; silsesquioxanes; nanoparticlecomposites including those that include nanowires; quantum dots;nanorods; abrasives; metal nanoparticles; sinterable metal powders;carbon composites comprising graphene, carbon nanotubes, and fullerenes;conductive composites; inherently conductive (conjugated) polymers;electrically active materials (anodic, cathodic, etc.); compositescomprising catalysts; low surface energy materials; and fluorinatedpolymers or composites.

The backfill layer can comprise any material as long as it has thedesired rheological and physical properties discussed previously.Typically, the backfill layer is made from a polymerizable compositioncomprising monomers which are cured using actinic radiation, e.g.,visible light, ultraviolet radiation, electron beam radiation, heat andcombinations thereof. Any of a variety of polymerization techniques,such as anionic, cationic, free radical, condensation or others may beused, and these reactions may be catalyzed using photo, photochemical orthermal initiation. These initiation strategies may impose thicknessrestrictions on the backfill layer, i.e the photo or thermal triggermust be able to uniformly react throughout the entire film volume.Useful polymerizable compositions comprise functional groups known inthe art, such as epoxide, episulfide, vinyl, hydroxyl, allyloxy,(meth)acrylate, isocyanate, cyanoester, acetoxy, (meth)acrylamide,thiol, silanol, carboxylic acid, amino, vinyl ether, phenolic, aldehyde,alkyl halide, cinnamate, azide, aziridine, alkene, carbamates, imide,amide, alkyne, and any derivatives or combinations of these groups. Themonomers used to prepare the backfill layer can comprise polymerizableoligomers or copolymers of any suitable molecular weight such asurethane(meth)acrylates, epoxy(meth)acrylates, polyester(meth)acrylates)and the like. The reactions generally lead to the formation of athree-dimensional macromolecular network and are known in the art asnegative-tone photoresists, as reviewed by Shaw et al., “Negativephotoresists for optical lithography”, IBM Journal of Research andDevelopment (1997) 41, 81-94. The formation of the network may occurthrough either through covalent, ionic, or hydrogen bonding or throughphysical crosslinking mechanisms such as chain entanglement. Thereactions can also be initiated through one or more intermediatespecies, such as free-radical initiators, photosensitizers, photoacidgenerators, photobase generators, or thermal acid generators. Othermolecular species may be involved in network formation as well, such ascrosslinker molecules containing two or more functional groups known inthe art to be reactive with the previously mentioned molecular species.

Reinforced silicone polymers can be used for the backfill layer, due totheir high chemical stability and excellent adhesion to glass.Therefore, no adhesion promotion layer is necessary for adhesion toglass substrates. Silicones are also well known not to adhere to otherpolymers, which makes this material straightforward to release frommicrostructured polymer tools, but difficult to transfer as onecomponent in a dyad, unless the other component is also a silicone. Onesuch silicone formulation, used in Example 4, is known as SYLGARD 184(Dow Corning, Midland, Mich.), which is a 2-component mixture ofpolydimethylsiloxane and vinylsiloxane mixed with hydrosiloxane and aplatinum catalyst. Slight heating of this mixture causes the siliconenetwork to form via platinum-catalyzed hydrosilylation curing reaction.Other silicones and catalysts can be used to the same effect, asdemonstrated in Example 5. Gelest Inc. (Morrisville, Pa.) manufactures awide variety of siloxanes functionalized with various reactive groups(epoxy, carbinol, mercapto, methacryloxy amino, silanol) for example.Gelest also sells these siloxanes pre-compounded with various additives,such as fully condensed silica nanoparticles or MQ resins, to tune themechanical properties of the silicone network. Other platinum catalystscan also be used, such as (trimethyl)methyl cyclopentadenyl platinum(IV) (Strem Chemicals Inc., Newburyport, Mass.), which activates viaultraviolet radiation but still requires a subsequent thermal cure.Photocurable silicone systems are advantageous because as long as theyare kept in the dark, their viscosity decreases with increasingtemperature, allowing bubbles to escape and better penetration intonanostructured tools.

Different varieties of the above materials can be synthesized withhigher refractive index by incorporating nanoparticles or metal oxideprecursors in with the polymer resin. Silecs SC850 material is amodified silsesquioxane (n≈1.85) and Brewer Science high index polyimideOptiNDEX D1 material (n˜1.8) are examples in this category. Othermaterials include a copolymer of methyltrimethoxysilane (MTMS) andbistriethoxysilylethane (BTSE) (Ro et. al, Adv. Mater. 2007, 19,705-710). This synthesis forms readily soluble polymers with very small,bridged cyclic cages of silsesquioxane. This flexible structure leads toincreased packing density and mechanical strength of the coating. Theratio of these copolymers can be tuned for very low coefficient ofthermal expansion, low porosity and high modulus.

In some embodiments, the backfill layer can include polyvinylsilsesquioxane polymers. These polymers can be prepared by thehydrolysis of vinyltriethoxysilane

Upon polymerization, typically by the addition of a photoinitiatorfollowed by exposure to ultraviolet radiation, a three dimensionalnetwork is formed by free radical polymerization of the many vinylgroups.

The backfill material typically can meet several requirements. First, itcan adhere and conform to the structured surface of the template layeron which it is coated. This means that the viscosity of the coatingsolution should be low enough to be able to flow into very smallfeatures without the entrapment of air bubbles, which will lead to goodfidelity of the replicated structure. If it is solvent based, it shouldbe coated from a solvent that does not dissolve or swell the underlyingtemplate layer, which would cause cracking or swelling of the backfill.It is desirable that the solvent has a boiling point below that of thetemplate layer glass transition temperature. Preferably, isopropanol,butyl alcohol and other alcoholic solvents have been used. Second, thematerial should cure with sufficient mechanical integrity (e.g., “greenstrength”). If the backfill material does not have enough green strengthafter curing, the backfill pattern features will slump and replicationfidelity will degrade. Third, for some embodiments, the refractive indexof the cured material should be tailored to produce the proper opticaleffect. Other substrates of a different refractive index can also beused for this process, such as sapphire, nitride, metal, polyimide, oroxide. Fourth, the backfill material should be thermally stable (e.g.,showing minimal cracking, blistering, or popping) above the temperatureof the upper range of the future process steps of the substrate.Typically the materials used for this layer undergo a condensationcuring step, which causes shrinkage and the build-up of compressivestresses within the coating. There are a few materials strategies whichare used to minimize the formation of these residual stresses which havebeen put to use in several commercial coatings which satisfy all of theabove criteria.

It can be advantageous to adjust the refractive index of both thebackfill and planarization layers. For example, in OLED light extractionapplications, the nanostructure imparted by the lamination transfer filmis located at a structured interface of the backfill and planarizationlayers. The backfill layer has a first side at the structured interfaceand a second side coincident with an adjacent layer. The planarizationlayer has a first side at the structured interface and a second sidecoincident with an adjacent layer. In this application, the refractiveindex of the backfill layer is index matched to the adjacent layer tothe backfill layer opposite the structured interface, while therefractive index of the planarization layer is index matched to theadjacent layer to the planarization layer opposite the structuredinterface.

Nanoparticles can be used to adjust refractive index of the backfill andplanarization layers. For example, in acrylic coatings, silicananoparticles (n≈1.42) can be used to decrease refractive index, whilezirconia nanoparticles (n≈2.1) can be used to increase the refractiveindex. If the index difference is large between the nanoparticles andbinder, a haze will develop inside the bulk of the coating. Forapplications in which haze is a desirable attribute (e.g., uniform lightdistribution in OLED solid state lighting elements), this limit can beexceeded. There is also a limit to the concentration of nanoparticles inthe resin before particle aggregation begins to occur, thereby limitingthe extent to which refractive index of the coating can be tuned.

TABLE 1 Thermally Stable Backfill Materials of Low and High RefractiveIndex Material Name or Trade Designation Type Available from TecheGlasGRx resins T-resin (methyl TechneGlas (Perrysburg, silsesquioxane) Ohio)HSG-510 T-resin (methyl Hitachi Chemical (Tokyo, silsesquioxane) Japan)ACCUGLASS 211 T-Q resin (methyl Honeywell (Tempe, AZ) silsesquioxane)HARDSIL AM silica nanocomposite Gelest Inc (Morrisville, PA) MTMS-BTSEbridged National Institute of Copolymer silsesquioxane Standards andTechnology (Ro et. al, Adv. Mater. (Gaithersburg, MD) 2007, 19, 705-710)PERMANEW 6000 silica-filled methyl- California Hardcoat (Chulapolysiloxane polymer Vista, CA) containing a latent heat-cure catalystsystem FOX Flowable OXide hydrogen Dow Corning (Midland, silsesquioxaneMI) ORMOCER, silicone hybrid Micro Resist GmBH ORMOCLAD, (Berlin,Germany) ORMOCORE SILECS SCx resins silicone hybrid Silecs Oy (Espoo,Finland) (n = 1.85) OPTINDEX D1 soluble polyimide Brewer Science (Rolla,(n = 1.8) MO) CORIN XLS resins soluble polyimide NeXolve Corp.(Huntsville, AL) CERASET resins polysilazanes KiON Specialty Polymers(Charlotte, NC) BOLTON metals low melting metal Bolton Metal Products(Bellafonte, PA) CYCLOTENE resins benzocyclobutane Dow Chemical(Midland, polymers MI) SYLGARD 184 silicone network Dow Corning(Midland, polymer MI)

Adhesion Promoting Layer Materials

The adhesion promoting layer can be implemented with any materialenhancing adhesion of the transfer film to the receptor substratewithout substantially adversely affecting the performance of thetransfer film. The exemplary materials for the backfill andplanarization layers can also be used for the adhesion promoting layer.A typical material for the adhesion promoting layer is the CYCLOTENEresin identified in Table 1. Other useful adhesion promoting materialsuseful in the disclosed articles and methods include photoresists(positive and negative), self-assembled monolayers, silane couplingagents, and macromolecules. In some embodiments, silsesquioxanes canfunction as adhesion promoting layers. Other exemplary materials mayinclude benzocyclobutenes, polyimides, polyamides, silicones,polysiloxanes, silicone hybrid polymers, (meth)acrylates, and othersilanes or macromolecules functionalized with a wide variety of reactivegroups such as epoxide, episulfide, vinyl, hydroxyl, allyloxy,(meth)acrylate, isocyanate, cyanoester, acetoxy, (meth)acrylamide,thiol, silanol, carboxylic acid, amino, vinyl ether, phenolic, aldehyde,alkyl halide, cinnamate, azide, aziridine, alkene, carbamates, imide,amide, alkyne, and any derivatives or combinations of these groups.

Release Liners

The backfill layer can, optionally, be covered with a temporary releaseliner. The release liner can protect the patterned structured backfillduring handling and can be easily removed, when desired, for transfer ofthe structured backfill or part of the structured backfill to a receptorsubstrate. Exemplary liners useful for the disclosed patternedstructured tape are disclosed in PCT Pat. Appl. Publ. No. WO 2012/082536(Baran et al.).

The liner may be flexible or rigid. Preferably, it is flexible. Asuitable liner (preferably, a flexible liner) is typically at least 0.5mil thick, and typically no more than 20 mils thick. The liner may be abacking with a release coating disposed on its first surface.Optionally, a release coating can be disposed on its second surface. Ifthis backing is used in a transfer article that is in the form of aroll, the second release coating has a lower release value than thefirst release coating. Suitable materials that can function as a rigidliner include metals, metal alloys, metal-matrix composites, metalizedplastics, inorganic glasses and vitrified organic resins, formedceramics, and polymer matrix reinforced composites.

Exemplary liner materials include paper and polymeric materials. Forexample, flexible backings include densified Kraft paper (such as thosecommercially available from Loparex North America, Willowbrook, Ill.),poly-coated paper such as polyethylene coated Kraft paper, and polymericfilm. Suitable polymeric films include polyester, polycarbonate,polypropylene, polyethylene, cellulose, polyamide, polyimide,polysilicone, polytetrafluoroethylene, polyethylenephthalate,polyvinylchloride, polycarbonate, or combinations thereof. Nonwoven orwoven liners may also be useful. Embodiments with a nonwoven or wovenliner could incorporate a release coating. CLEARSIL T50 Release liner;silicone coated 2 mil polyester film liner, available from Solutia/CPFilms, Martinsville, Va., and LOPAREX 5100 Release Liner,fluorosilicone-coated 2 mil polyester film liner available from Loparex,Hammond, Wis., are examples of useful release liners.

The release coating of the liner may be a fluorine-containing material,a silicon-containing material, a fluoropolymer, a silicone polymer, or apoly(meth)acrylate ester derived from a monomer comprising analkyl(meth)acrylate having an alkyl group with 12 to 30 carbon atoms. Inone embodiment, the alkyl group can be branched. Illustrative examplesof useful fluoropolymers and silicone polymers can be found in U.S. Pat.No. 4,472,480 (Olson), U.S. Pat. Nos. 4,567,073 and 4,614,667 (bothLarson et al.). Illustrative examples of a useful poly(meth)acrylateester can be found in U. S. Pat. Appl. Publ. No. 2005/118352 (Suwa). Theremoval of the liner shouldn't negatively alter the surface topology ofthe backfill layer.

Other Additives

Other suitable additives to include in the backfill and adhesionpromotion layer are antioxidants, stabilizers, antiozonants and/orinhibitors to prevent premature curing during the process of storage,shipping and handling of the film. Preventing premature curing canmaintain the tack required for lamination transfer in all previouslymentioned embodiments. Antioxidants can prevent the formation of freeradical species, which may lead to electron transfers and chainreactions such as polymerization. Antioxidants can be used to decomposesuch radicals. Suitable antioxidants may include, for example,antioxidants under the IRGANOX tradename. The molecular structures forantioxidants are typically hindered phenolic structures, such as2,6-di-tert-butylphenol, 2,6-di-tert-butyl-4-methylphenol, or structuresbased on aromatic amines. Secondary antioxidants are also used todecompose hydroperoxide radicals, such as phosphites or phosphonites,organic sulphur containing compounds and dithiophosphonates. Typicalpolymerization inhibitors include quinone structures such hydroquinone,2,5 di-tert-butyl-hydroquinone, monomethyl ether hydroquinone orcatechol derivatives such as 4-tert butyl catechol. Any antioxidants,stabilizers, antiozonants and inhibitors used must be soluble in thebackfill and adhesion promotion layer.

EXAMPLES

All parts, percentages, ratios, etc. in the examples are by weight,unless noted otherwise. Solvents and other reagents used were obtainedfrom Sigma-Aldrich Corp., St. Louis, Mo. unless specified differently.

Examples 1 and 2 use the procedures illustrated in FIG. 1.

Example 1 Hardcoat with Adhesion Promotion Layer Template/ReleaseCoating

The base film was a flame treated 2 mil (50 μm) KAPTON H, primed with aactinic radiation cured primer comprising 50/50 blend of UVACURE 1500(Cytec, Woodland Park, N.Y.) and trimethylolpropane triacrylate (TMPTA)with 1% OMAN 071 photoinitiator (available from Gelest, Morrisville,Pa.).

The replicating resin was a 75/25 blend of dipentaerythritolpentaacrylate (SR 399) and 1,6-hexanediol diacrylate (SR 238), bothavailable from Sartomer, Exton, Pa., with a photoinitator packagecomprising 1% DAROCUR 1173 (available from Ciba, Basel, Switzerland,1.9% triethanolamine, 0.5% OMAN 071, and 0.3% methylene blue.Replication of the resin was conducted at 20 feet/minute (fpm) with thetool temperature at 137° F. (58.3° C.). Radiation from a Fusion “D” lampoperating at 600 W/in (236 W/cm) was transmitted through the film tocure the resin while in contact with the tool. The composite film wasremoved from the tool and the patterned side of the film was postradiation cured using a Fusion “D” lamp operating at 360 W/in (142 W/cm)while in contact with a chill roll heated to 100° F. (37.8° C.).

The replicated template film was primed with argon gas at a flow rate of250 standard cc 3/min (SCCM), a pressure of 25 mTorr and RF power of1000 Watts for 30 seconds. Subsequently, the samples were exposed totetramethylsilane (TMS) plasma at a TMS flow rate of 150 SCCM but noadded oxygen; this corresponds to an atomic ratio of oxygen to siliconof about 0. The pressure in the chamber was 25 mTorr, the RF power 1000Watts was maintained for 10 seconds.

Backfill Coating

A length (120 cm×30 cm) of the replicated template film was placed on aflat metal plate. PERMANEW 6000 L510-1 (available from CaliforniaHardcoat, Chula Vista, Calif.) was diluted to 10% w/w in isopropanol,and brought to room temperature. Approximately 5 mL of PERMANEW 6000L510-1 was applied to the replicated film and then coated with a #10Mayer bar onto the film to produce a backfilled sample. The film wasdried at 50° C. for 10 minutes. The sample was then allowed to cool toroom temperature.

Adhesion Promoter Coating

Polished glass slides, 50 mm×50 mm, were first cleaned with a lint freecloth, then sonicated in a wash chamber for 20 minutes with detergent,then 20 minutes in each of two cascading rinse chambers with heatedwater. The slides were then dried for 20 minutes in an oven withcirculating air. The slides were mounted on a the vacuum chuck of aModel WS-6505-6npp/lite spin coater. A vacuum of 64 kPa (48 mm of Hg)was applied to hold the sample to the chuck. The spin coater wasprogrammed for 500 RPM for 5 seconds (coating application step) then2000 RPM for 15 sec (spin step), then 1000 RPM for 10 seconds (drystep).

A solution of (CYCLOTENE 3022 63 resin, 63% w/w stock, from DOW ChemicalCompany, Midland, Mich.) was diluted to 25% w/w in mesitylene.Approximately 1-2 mL of the CYCLOTENE solution 25% w/w was applied tothe sample during the coating application portion of the spin cycle. Thesample was then removed from the spin coater and put on a hotplate at90° C. for 5 minutes while covered with an aluminum tray. The sample wasallowed to cool to room temperature.

Lamination

The backfilled template was laminated at 230° F. (110° C.), coating sidedown, to the CYCLOTENE-coated cleaned glass slide using a thermal filmlaminator (GBC Catena 35, GBC Document Finishing, Lincolnshire, Ill.).The laminated sample was removed from the hotplate and allowed cool toroom temperature.

Firing

The template tool was peeled from the sample, transferring thereplicated backfill material to the glass slide. The laminated samplewas placed in a box furnace and brought from 25° C. to 500° C. at a rateof about 5° C./min. The furnace was held at 500° C. for one hour, thenthe furnace and sample were allowed to cool down naturally. The resultwas a transparent glass substrate having nanostructures and is shown inFIG. 12.

Example 2 Acrylate Structure with Radiation Releasable PSA AdhesionPromotion Layer

A release coated template layer was constructed as in Example 1.

Backfill Coating

An acrylate resin system (2-propenoic acid(1-methylethylidene)bis[(2,6-dibromo-4,1-phenylene)oxy(2-hydroxy-3,1-propanediyl)]ester,phenoxyethyl acrylate and trimethylol propane triacrylate (65/25/10)containing photoinitiator (0.1% 2,4,6-trimethylbenzoyldiphenylphosphineoxide and 0.35% 2-hydroxy-2-methyl-1-phenyl-propan-1-one) as describedin U. S. Pat. Appl. Publ. No. 2006/0004166 (Olson) was knife coated ontothe replicated template film with as thin a layer as possible. Thefunction of this layer is to just fill the nanostructure with a hardacrylate that would add durability to the final film. The acrylatecoated template was cured in a belt fed cure chamber (RPC industries)fitted with a Fusion H bulb in Nitrogen (2 passes, 20 fpm). The samplewas removed from the chamber, and cooled to room temperature.

A radiation releasable pressure sensitive adhesive (PSA) system(IOA/MA/AA (57.5/35/7.5) was mixed with 25% w/w SR494 (pentaerithrotoltetraacrylate from Sartomer Co.) and 1 wt % DAROCUR 1173 (photoinitiatorfrom Ciba/BASF). The mixture was diluted to 20% solids in ethylacetate/toluene. The PSA system disclosed above was knife coated onto asection of the cured, filled template film disclosed above with a gap of4 mil (100 μm). The film was dried at 70° C. for 10 minutes. The samplewas then allowed to cool to room temperature.

Lamination

The sample was hand laminated to a pane of glass at room temperature.The glass was then heated to 90° C. on a hotplate, and hand laminatedagain. The sample was cured in a belt fed cure chamber (RPC industries)fitted with a Fusion H bulb in nitrogen (2 passes, 20 fpm). The samplewas removed from the chamber, and cooled to room temperature. ThePolyethylene replicated template was removed from the sample, leavingcured nanostructure on the glass substrate.

Examples 3-6 use the procedures illustrated in FIG. 3.

Example 3 Radiation Releasable PSA

A polymeric pressure sensitive adhesive composition with multifunctionalacrylate addition, which exhibits substantial initial adhesion, but uponradiation curing, adhesion is significantly reduced and the pressuresensitive adhesive is easily removable from the template film.

A release coated template layer was constructed as in Example 1.

Backfill Coating

A radiation releasable pressure sensitive adhesive (PSA) system madefrom isooctyl acylate/methacrylate/acrylic acid, 26% solids by weight inethyl acetate and toluene, is a copolymer with a monomer ratio of57.5/35/7.5, and is prepared as described in U.S. Pat. No. RE 24,906(Ulrich). This PSA system was mixed with 25% w/w SR494 (pentaerithrotoltetraacrylate from Sartomer Co.) and 1 wt % DAROCUR 1173 (photoinitiatorfrom Ciba/BASF). The mixture was diluted to 20% solids in ethylacetate/toluene. The PSA system disclosed above was coated onto asection of the replicated template film disclosed above using a doctorblade. The film was dried at 90° C. for 10 minutes. The sample was thenallowed to cool to room temperature.

Lamination

The sample was hand laminated to a pane of glass at room temperature.The glass was then heated to 90° C. on a hotplate, and hand laminatedagain. The sample was cured in a belt fed cure chamber (RPC industries)fitted with a Fusion H bulb in nitrogen (2 passes, 20 fpm). The samplewas removed from the chamber, and cooled to room temperature. Thereplicated template was removed from the sample, leaving curednanostructure on the glass substrate.

Example 4

QPAC 100 (Empower Materials) was coated onto the backside of a CLEARSILsilicone release liner T-50 (available from CPFilms Inc, Dubvai, UAE)and embossed with nanoscale features as disclosed in U.S. patentapplication Ser. No. 13/553,987, entitled “STRUCTURED LAMINATIONTRANSFER FILMS AND METHODS”, filed Jul. 20, 2012. The coated film wasapproximately four microns thick, and the embossed impressions were of600 nm pitch, with a 1:1 height to pitch ratio sawtooth pattern. Asilicone material SYLGARD 184 (Dow) was prepared according to literatureprocedures. The SYLGARD 184 base resin was mixed with the crosslinker ina 10:1 ratio in a plastic cup. The mixture was slowly stirred for threeminutes with a spatula until a homogenous solution was obtained. Themixture was placed in a dessicator under reduced pressure for about 1hour to remove all trapped air bubbles from the resin mixture. Themixture was poured on top of the embossed QPAC100 and notch-bar coatedwith a 1 mil gap, and then placed in a vacuum oven at 80° C. for 3hours. The vacuum environment was used to help remove entrapped air fromthe nanoscale features during the curing process. After the cure, theSYLGARD 184/QPAC100/T50 stack was placed in a plasma chamber along withglass microscope slides. Both materials were exposed to an oxygen plasmafor 1 minute (75 W, 0.6 mTorr, 50 sccm 02), and then the SYLGARD 184stack was flipped over and brought into contact immediately with theglass side while laminating at 0.1 ft/min (3.0 cm/min). The samples wereheated for 30 minutes in a 120° C. oven to bond the silicone and theglass surfaces together. Finally, the QPAC100/T50 mold was peeled off ofthe SYLGARD 184, leaving behind a negative replica of the nanoembossedfeatures.

Example 5

QPAC 100 (Empower Materials) was coated onto the backside of a T50release liner and embossed with nanoscale features as disclosed inExample 4. The coated film was approximately four microns thick, and theembossed impressions were of 600 nm pitch, with a 1:1 height to pitchratio sawtooth pattern disclosed in IS N019969. A UV curable siliconematerial was prepared according to the following procedures. VQM-135(Gelest) base resin was mixed with a crosslinker SYL-OFF 7678 (Dow) in a10:1 ratio in a plastic cup. 10 ppm of a platinum photohydrosilylationcatalyst (MeCp)PtMe₃, Alfa Aesar) was added to the resin solutionstirred for three minutes with a spatula. The mixture was placed on an80° C. hotplate for 15 minutes to reduce viscosity before coating. Themixture was poured on top of the embossed QPAC100 and notch-bar coatedwith a 1 mil (25 μm) gap, and then cured under a high-intensityultraviolet lamp (Fusion D Bulb, 3 passes at 20 feet/min). ThePSE-002/QPAC100/T50 stack was flipped over and brought into contactimmediately with an oxygen plasma treated glass side while laminating at0.1 ft/min (3.0 cm/min). The samples were heated for 20 minutes in a120° C. oven to complete the cure of the silicone and bond the siliconeto the glass. After cooling the sample on an aluminum plate, theQPAC100/T50 mold was peeled off of the PSE-002, leaving behind anegative replica of the nanoembossed features.

Example 6

QPAC 100 (Empower Materials) was coated onto the backside of a T50release liner following the procedure in Example 4. The coated film wasapproximately four microns thick, and the embossed impressions were of600 nm pitch, with a 1:1 height to pitch ratio sawtooth pattern. HARDSILAM hardcoat solution was purchased from Gelest, notch-bar coated on topof the embossed QPAC100 with a 1 mil (25 μm) gap, and dried overnight at90° C. (15 hours). A UV-curable silicone material was prepared accordingto the following procedures. VQM-135 (Gelest) base resin was mixed witha crosslinker SYL-OFF 7678 (Dow) in a 10:1 ratio in a plastic cup. 10ppm of a platinum photohydrosilylation catalyst ((MeCp)PtMe₃, AlfaAesar) was added to the resin solution and stirred for three minuteswith a spatula. The mixture was poured on top of the cured HARDSIL AMand notch-bar coated with a with a 2 mil (50 μm) gap, and then curedunder a high-intensity ultraviolet lamp (Fusion D Bulb, 3 passes at 20feet/min), followed by a 90° C. overnight cure (15 hrs). The PSE-002 topsurface and a glass slide was exposed to oxygen plasma for 1 minute (75W, 0.6 mTorr, 50 sccm O₂), and then the two materials brought intocontact immediately with a lamination at 0.1 ft/min (3.0 cm/min). A dropof water in between the two surfaces improved uniformity during thelamination transfer step. The samples were heated for 5 minutes on a120° C. hotplate to bond the silicone to the glass slide. After coolingthe sample on an aluminum plate, the QPAC100/T50 mold was peeled off ofthe Hardsil AM/PSE-002/Glass, leaving behind a negative replica of thenanoembossed features on glass.

Examples 7 and 8 use the processes disclosed in FIG. 2

Example 7 Patterned Hardcoat

A release coated template layer was constructed as in Example 1.

Backfill Coating

A length (120 cm×30 cm) of the replicated template film was placed on aflat metal plate. PERMANEW 6000 L510-1 (available from CaliforniaHardcoat, Chula Vista, Calif.) was diluted to 10% w/w in isopropanol,and brought to room temperature. 5 mL of PERMANEW 6000 L510-1 wasapplied to the replicated film, then Mayer bar (#10) coated onto thefilm to produce a backfilled sample. The film was dried at 50° C. for 10minutes. The sample was then allowed to cool to room temperature.

Patterned Adhesion Layer

Polished glass slides, 50 mm×50 mm, were first cleaned with a lint freecloth, then sonicated in a wash chamber for 20 minutes with detergent,then 20 minutes in each of two cascading rinse chambers with heatedwater. The slides were then dried for 20 minutes in an oven withcirculating air. The slides were pre-baked at 80° C. for 20 to 30minutes. A slide was mounted on the chuck of a Karl Suss spin coater.The spin coater was programmed for 4000 RPM for 40 seconds with a 2000rpm ramp. A solution of TOK TELR-P003PM positive photoresist (Tokyo OhkaKogyo Co., Ltd., Kanagawa, JAPAN was applied to the sample during thecoating application portion of the spin cycle. The sample was thenremoved from the spin coater and soft baked on a hotplate at 95° C. for20 minutes. The coated sample was imaged with a pixel size test patternwith constant pitch and varying area with an UV intensity of 66 mJ/cm2for 2.44 seconds. The resist was developed with MICROPOSIT MF-319developer (Rohm and Haas Electronic Materials LLC, Marlborough, Mass.01752 United States of America) for 60 seconds with agitation, thenrinsed in cascading DI water and dried with nitrogen. The sample wasthen hardbaked by first preheating to 200° C. for 2-3 minutes, thenbaked on a hotplate at 250° C. for 30 minutes.

Lamination

The backfilled template film was laminated at 230° F. (110° C.), coatingside down, to the patterned photoresist coated cleaned glass slide usinga thermal film laminator (GBC Catena 35, GBC Document Finishing,Lincolnshire, Ill.). The laminated sample was removed from the hotplateand allowed cool to room temperature. The template tool was peeled fromthe sample, transferring the replicated backfill material to thephotoresist on the glass slide. The result was a transparent glasssubstrate having patterned nanostructures and is depicted in FIG. 13.

Example 8 Patterned Hardcoat Sacrificial Material Layer Coating andEmbossing

A 5 wt % solution of QPAC 100 in 1,3-dioxolane was delivered at a rateof 30 cm³/min to a 10.2 cm (4 inch) wide slot-type coating die incontinuous film coating apparatus. The solution was coated on thebackside of a 0.051 mm (0.002 inch) thick T50 silicone release liner.The coated web traveled approximately 2.4 m (8 ft) before entering a 9.1m (30 ft) conventional air floatation drier with all 3 zones set at65.5° C. (150° F.). The substrate was moving at a speed of 3.05 m/min(10 ft/min) to achieve a wet coating thickness of about 80 micrometers.

The coated film was then embossed in a nip under a pressure of 1.75kN/cm (1000 pounds per lineal inch) against a metal master tool with 600nm pitch linear sawtooth grooves at a temperature of 110° C. (230° F.).Embossing line speed was 0.61 m/min (2 ft/min).

Backfill Coating

A section of the embossed film was treated with an air corona in a rollto roll process using a dual ceramic bar apparatus powered by aUniversal Compak power supply (Enercon Industries Corporation, MenomoneeFalls, Wis.). The system was configured to apply 0.75 J to the sample at1.5 m/min (5 ft/min) in air, with a 3.2 mm (⅛ inch) gap between theceramic bar and the sample.

A sample of the corona treated embossed film (≈2 in×3 in) was coatedwith PERMANEW 6000 L510-1, which was applied to the embossed film sampleby spin coating. Prior to spin coating, the PERMANEW 6000 was diluted to17.3 wt % in isopropanol and filtered through a 0.8 μm filter. A glassmicroscope slide was used to support the film during the coatingprocess. The spin parameters were 500 rpm/3 sec (solution application),and 3000 rpm/10 sec (spin down). The sample was removed from spin coaterand placed on a hotplate at 50° C. for 30 min to complete the dryingprocess. After drying, the backfilled sample was placed on a hotplate at70° C. for 4 hours to cure the PERMANEW 6000.

Patterned Adhesion Layer

Polished glass slides, 50 mm×50 mm, were first cleaned with a lint freecloth, then sonicated in a wash chamber for 20 minutes with detergent,then 20 minutes in each of two cascading rinse chambers with heatedwater. The slides were then dried for 20 minutes in an oven withcirculating air. The slides were pre-baked at 80° C. for 20 to 30minutes. A slide was mounted on the chuck of a Karl Suss spin coater.The spin coater was programmed for 4000 RPM for 40 seconds with a 2000rpm ramp. A solution of TOK TELR-P003PM positive photoresist (Tokyo OhkaKogyo Co., Ltd., Kanagawa, JAPAN) was applied to the sample during thecoating application portion of the spin cycle. The sample was thenremoved from the spin coater and soft baked on a hotplate at 95° C. for20 minutes.

The coated sample was imaged with a pixel size test pattern withconstant pitch and varying area with an ACTINIC intensity of 66 mJ/cm2for 2.44 seconds. The resist was developed with MICROPOSI MF 319developer (Rohm and Haas Electronic Materials LLC, Marlborough, Mass.01752 United States of America) for 60 seconds with agitation, thenrinsed in cascading DI water and dried with nitrogen. The sample wasthen hardbaked by first preheating to 200° C. for 2-3 minutes, thenbaked on a hotplate at 250° C. for 30 minutes.

Lamination and Autoclaving

A drop of deionized water was applied to the patterned glass slide topromote adhesion between the PERMANEW 6000 and the patterned photoresistand the backfilled template film was laminated at 230° F. (110° C.),coating side down, to the patterned photoresist coated cleaned glassslide using a thermal film laminator (GBC Catena 35, GBC DocumentFinishing, Lincolnshire, Ill.). The laminated sample was allowed cool toroom temperature. To remove any air bubbles left by the lamination step,the laminated sample was placed in an Autoclave at 75° C. and 6.5 psifor 30 mins. The T50 film was peeled from the sample, transferring thesacrificial template and backfill material to the patterned glass slide.

Sacrificial Template Removal

The laminated sample was placed in a tube furnace at room temperature.The furnace was purged with nitrogen gas for the duration of theexperiment. The temperature was then ramped from 25° C. to 300° C. at10° C./min and held at 300° C. for 3 hours. The furnace and samplecooled to ambient temperature. The resulting nanostructured sample wastransparent and exhibited iridescence that is characteristic of a linearoptical grating.

Removal of Nanostructure from Unpatterned Areas

After removal of the sacrificial template, the nanostructured sample wasplaced in a glass beaker filled with deionized water and the beaker wasplaced in an ultrasonic cleaner (PC3 by L&R Ultrasonics of Kearny, N.J.)for 30 min. The result was a transparent glass substrate havingpatterned nanostructures. The results are shown in FIG. 14. The lighterrectangles are areas where the nanostructure was not transferred to thesubstrate.

Example 9 uses the procedure disclosed in FIG. 8.

Example 9 Vinyl Silsesquioxane Patterned with Vias

A release coated template layer was constructed as in Example 1.

Preparation of Vinylsilsesquioxane

Vinyltriethoxysilane (100 g) (Gelest Inc., Morrisville, Pa. USA),deionized water (50 g), and oxalic acid (0.5 g) (Sigma-Aldrich, St.Louis, Mo.) were mixed together at room temperature in a 500 mL roundbottom flask equipped with a condenser. The mixture was stirred at roomtemperature for 6-8 hrs followed by the evaporation of the solvents(water/ethanol mixture). The resulting viscous liquid was dissolved inmethyl ethyl ketone (100 mL) and washed three-times with deionized water(100 mL). After washing, the methyl ethyl ketone and residual water wasevaporated under reduced pressure to yield vinylsilsesquioxane asviscous liquid. A vinylesilsesquioxane radiation curable system wasprepared by redisolving the vinylsilsesquioxane in methyl ethyl ketoneto a 30% w/w solution with 1% w/w IRGACURE184 (photoinitiator fromCiba/BASF).

Backfill Coating

A piece of the template film slightly larger than 5.1 cm×7.6 cm (2inch×3 inch) was adhered to a 1 mm thick 5.1 cm×7.6 cm (2 inch×3 inch)glass microscope slide (available from VWR International, Radnor Pa.)with tape. The glass slide and sample were then put on a ModelWS-6505-6npp/lite spin coater (available from Laurell TechnologiesCorporation, North Wales Pa.) directly on the vacuum chuck. A vacuum of64 kPa (19 inches of Hg) was applied to hold the sample to the chuck.The spin coater was programmed for 500 RPM for 5 seconds (coatingapplication step) then 1000 RPM for 15 sec (spin step), then 1000 RPMfor 20 seconds (dry step). Approximately 1-2 mL of the vinylsilsesquioxane radiation curable system was applied to the template filmduring the coating application portion of the spin cycle, to produce abackfilled sample.

The sample was removed from spin coater and placed on a hotplate at 50°C. for 30 minutes, covered with an aluminum tray. The sample was thenallowed to cool to room temperature. The sample was laminated at roomtemperature, coating side down, to a fluorinated/siliconized releaseliner using a thermal film laminator (GBC Catena 35, GBC DocumentFinishing, Lincolnshire, Ill.). The laminated sample was allowed cool toroom temperature. The coated sample was then imaged with a nickel onquartz phototool through the release liner, in a belt fed cure chamber(RPC industries) fitted with a Fusion H bulb (1 pass, 25 fpm). Thesample was removed from the chamber, and cooled to room temperature. Therelease liner was removed from the sample, and then laminated at 230° F.(110° C.), coating side down, to a 1 mm thick 5.1 cm×7.6 cm (2 inch×3inch) glass microscope slide (available from VWR International, RadnorPa.) using a thermal film laminator (GBC Catena 35, GBC DocumentFinishing, Lincolnshire, Ill.). The laminated sample was allowed cool toroom temperature. The laminated sample was then cured in a belt fed curechamber (RPC industries) fitted with a Fusion H bulb in nitrogen (1pass, 25 fpm). The sample was removed from the chamber, and cooled toroom temperature. The template film was then removed from the sample,leaving a cured, patterned nanostructured layer on the glass (FIG. 15).

Example 10 uses the procedure illustrated in FIG. 6.

Example 10 Patterned Vinyl Silsesquioxane

A release coated template layer was constructed as in Example 1.Vinyl silsesquioxane was prepared as disclosed in Example 9.

Backfill Coating

A piece of the template film slightly larger than 5.1 cm×7.6 cm (2inch×3 inch) was adhered to a 1 mm thick 5.1 cm×7.6 cm (2 inch×3 inch)glass microscope slide (available from VWR International, Radnor, Pa.)with tape. The glass slide and sample were then put on a ModelWS-6505-6npp/lite spin coater (available from Laurell TechnologiesCorporation, North Wales Pa.) directly on the vacuum chuck. A vacuum of64 kPa (483 mm Hg) was applied to hold the sample to the chuck. The spincoater was programmed for 500 RPM for 5 seconds (coating applicationstep) then 1000 RPM for 15 sec (spin step), then 1000 RPM for 20 seconds(dry step). Approximately 1-2 mL of the vinyl silsesquioxane radiationcurable system was applied to the template film during the coatingapplication portion of the spin cycle, to produce a backfilled sample.

The sample was removed from spin coater and placed on a hotplate at 50°C. for 30 minutes, covered with an aluminum tray. The sample was thenallowed to cool to room temperature. The sample was laminated at roomtemperature, coating side down, to a fluorinated/siliconized releaseliner using a thermal film laminator (GBC Catena 35, GBC DocumentFinishing, Lincolnshire, Ill.). The laminated sample was allowed cool toroom temperature. The coated sample was then imaged with a nickel onquartz phototool through the release liner, in a belt fed cure chamber(RPC industries) fitted with a Fusion H bulb in nitrogen (1 pass, 25fpm). The sample was removed from the chamber, and cooled to roomtemperature. ACTINIC

The release liner was removed from the sample, and adhered to a 1 mmthick 5.1 cm×7.6 cm (2 inch×3 inch) glass microscope slide (availablefrom VWR International, Radnor Pa.) with tape, coating side up. Theglass slide and sample were then put on a Model WS-6505-6npp/lite spincoater (available from Laurell Technologies Corporation, North WalesPa.) directly on the vacuum chuck. A vacuum of 64 kPa (19 inches of Hg)was applied to hold the sample to the chuck. The spin coater wasprogrammed for 500 RPM for 5 seconds (coating application step) then1000 RPM for 15 sec (spin step), then 1000 RPM for 20 seconds (drystep). Approximately 1-2 mL of the vinyl silsesquioxane radiationcurable system was applied to the template film during the coatingapplication portion of the spin cycle, to produce a backfilled sample.

The sample was removed from spin coater and placed on a hotplate at 50°C. for 30 minutes, covered with an aluminum tray. The sample was thenallowed to cool to room temperature. The sample was laminated at roomtemperature, coating side down, to a 1 mm thick 5.1 cm×7.6 cm (2 inch×3inch) glass microscope slide (available from VWR International, RadnorPa.) using a thermal film laminator (GBC Catena 35, GBC DocumentFinishing, Lincolnshire, Ill.). The laminated sample was allowed cool toroom temperature.

The template film was then removed from the sample. The uncured areaswere allowed to reflow, effectively removing the nanostructure in theseareas. The laminated sample was then cured in a belt fed cure chamber(RPC industries) fitted with a Fusion H bulb in nitrogen (1 pass, 25fpm). The sample was removed from the chamber, and cooled to roomtemperature. This process produced a patterned, nanostructured samplewhere the unstructured areas retained material but did not retainstructure.

Example 11 and 12 use the procedure disclosed in FIG. 4.

Example 11 Patterned Vinyl Silsesquioxane

A release coated template layer was constructed as in Example 1.

Vinyl silsesquioxane was prepared as disclosed in Example 9.

Backfill Coating

A piece of the template film slightly larger than 5.1 cm×7.6 cm (2inch×3 inch) was adhered to a 1 mm thick 5.1 cm×7.6 cm (2 inch×3 inch)glass microscope slide (available from VWR International, Radnor Pa.)with tape. The glass slide and sample were then put on a ModelWS-6505-6npp/lite spin coater (available from Laurell TechnologiesCorporation, North Wales Pa.) directly on the vacuum chuck. A vacuum of64 kPa (19 inches of Hg) was applied to hold the sample to the chuck.The spin coater was programmed for 500 RPM for 5 seconds (coatingapplication step) then 1000 RPM for 15 sec (spin step), then 1000 RPMfor 20 seconds (dry step). Approximately 1-2 mL of the vinylsilsesquioxane radiation curable system was applied to the template filmduring the coating application portion of the spin cycle, to produce abackfilled sample.

The sample was removed from spin coater and placed on a hotplate at 50°C. for 30 minutes, covered with an aluminum tray. The sample was thenallowed to cool to room temperature. The sample was laminated at 230° F.(110° C.), coating side down, to a 1 mm thick 5.1 cm×7.6 cm (2 inch×3inch) glass microscope slide (available from VWR International, RadnorPa.) using a thermal film laminator (GBC Catena 35, GBC DocumentFinishing, Lincolnshire, Ill.). The laminated sample was allowed cool toroom temperature. The laminated sample was then imaged with a nickel onquartz phototool through the release liner in a belt fed cure chamber(RPC industries) fitted with a Fusion H bulb (1 pass, 25 fpm). Thesample was removed from the chamber, and cooled to room temperature. Thetemplate film was removed, and the uncured areas allowed to reflow for1-5 minutes at room temperature. The sample was then cured in a belt fedcure chamber (RPC industries) fitted with a Fusion H bulb in nitrogen (1pass, 25 fpm). The sample was removed from the chamber, and cooled toroom temperature. This process produced a patterned, nanostructuredsample where the unstructured areas retained material but did not retainstructure as shown in FIG. 19.

Materials

Abbreviation/ product name Description Available from 3-mercaptopropylChain Transfer Alfa Aesar, Ward trimethoxysilane Agent, 95% Hill, MAIsooctyl Acrylate Isooctyl Acrylate Sigma-Aldrich Chemical Company,Milwaukee, WI hydroxy-ethyl acrylate hydroxy-ethyl acrylate Alfa Aesar,Ward Hill, MA ethyl acetate solvent Honeywell International, Inc.,Morristown, NJ. NTB-1 15% wt aqueous titanium Denko Corporation, dioxidesol with pH at 4 Japan Phenyltrimethoxysilane Silane surface Alfa Aesar,Ward treatment, 97% Hill, MA PM 1-methoxy-2-propanol Alfa Aesar, WardHill, MA Vazo 67 2,2′-Azobis(2- Sigma-Aldrich methylbutyronitrile)Chemical Company, Milwaukee, WI

Preparative Example 1 Synthesis of Silane Functional Polymers Synthesisof Polymer Solution I

In an 8 ounce brown bottle, 27 g of isooctyl acrylate, 3.0 g ofhydroethyl acrylate, 2.25 g of 3-mercaptopropyl trimethoxysilane, 80 gethyl acetate, and 0.15 g of Vazo 67 were mixture together. The mixturewas bubbled under N₂ for 20 min, then, the mixture was placed in an oilbath at 70° C. for 24 hours. This resulted in an optical clear solutionwith a wt % solids of 31.04%.

Preparation of Optical Coupling Material

Into a 2 L round-bottom flask equipped with a dropping funnel,temperature controller, paddle stirrer, and distilling head, was charged177 g of NTB-1 sol (15% wt aqueous titanium dioxide sol with pH at 4,available from Denko Corporation, Japan) and 200 g of1-methoxy-2-propanol, which were mixed together. 3.24 g ofphenyltrimethoxysilane, 30 g of toluene, and Polymer Solution I wasadded under rapid stirring. After 15 min, the temperature was raised to48° C. and an additional 240 g of toluene was added. The mixture wasthen heated to 80° C. for 16 hours.

The temperature was allowed to return to room temperature and themixture was then transferred into a round flask. The solvent was removedusing a rotary evaporator to yield a white wet-cake like materials. Thenan additional 400 g of toluene was added. The solvents were furtherremoved using a rotary evaporator. The final product was a dispersion ofsurface treated TiO₂ nanoparticles in toluene. The weight percent solidsin the dispersions are given in the table below.

The solutions were coated on primed PET using a glass rod. The coatedsamples were dried in a vacuum oven for 5 minutes at 65° C. Afterdrying, the samples yielded optically clear and sticky coatings withbluish color in thick areas. The tack was measured as describedelsewhere and the refractive indexes of the materials were measuredusing a Metricon MODEL 2010 prism coupler (Metricon Corporation Inc.Pennington, N.J.) at 632.8 nm and are reported in the table below.

Example 12 Patterned Optical Coupling Layer on Glass

A release coated template layer was constructed as in Example 1.

Backfill Coating

A piece of the template film slightly larger than 5.1 cm×7.6 cm (2inch×3 inch) was adhered to a 1 mm thick 5.1 cm×7.6 cm (2 inch×3 inch)glass microscope slide (available from VWR International, Radnor Pa.)with tape. The glass slide and sample were then put on a ModelWS-6505-6npp/lite spin coater (available from Laurell TechnologiesCorporation, North Wales Pa.) directly on the vacuum chuck. A vacuum of64 kPa (19 inches of Hg) was applied to hold the sample to the chuck.The spin coater was programmed for 500 RPM for 5 seconds (coatingapplication step) then 1000 RPM for 15 sec (spin step), then 1000 RPMfor 20 seconds (dry step). Approximately 1-2 mL of the optical couplinglayer described above was applied to the template film during thecoating application portion of the spin cycle, to produce a backfilledsample.

The sample was removed from spin coater and placed on a hotplate at 50°C. for 30 minutes, covered with an aluminum tray. The sample was thenallowed to cool to room temperature. The sample was laminated at 230° F.(110° C.), coating side down, to a 1 mm thick 5.1 cm×7.6 cm (2 inch×3inch) glass microscope slide (available from VWR International, RadnorPa.) using a thermal film laminator (GBC Catena 35, GBC DocumentFinishing, Lincolnshire, Ill.). The laminated sample was allowed cool toroom temperature. The laminated sample was then imaged with a nickel onquartz phototool through the glass slide in a mask aligner.

The template film was removed, and the uncured areas allowed to reflowfor 1-5 minutes at room temperature. The sample was then cured in a beltfed cure chamber (RPC industries) fitted with a Fusion H bulb innitrogen (1 pass, 25 fpm). The sample was removed from the chamber, andcooled to room temperature. This process produced a patterned,nanostructured sample where the unstructured areas retained material butdid not retain structure.

Example 13 uses the procedure disclosed in FIG. 9.

Example 13 Embedded Low Index Dyad

A release coated template layer was constructed as in Example 1.

Backfill Coating

A piece of the template film slightly larger than 5.1 cm×7.6 cm (2inch×3 inch) was adhered to a 1 mm thick 5.1 cm×7.6 cm (2 inch×3 inch)glass microscope slide (available from VWR International, Radnor Pa.)with tape. The glass slide and sample were then put on a ModelWS-6505-6npp/lite spin coater (available from Laurell TechnologiesCorporation, North Wales Pa.) directly on the vacuum chuck. A vacuum of64 kPa (19 inches of Hg) was applied to hold the sample to the chuck.The spin coater was programmed for 500 RPM for 5 seconds (coatingapplication step) then 1000 RPM for 15 sec (spin step), then 1000 RPMfor 20 seconds (dry step). Approximately 1-2 mL of optical couplingmaterial described in Example 12 was applied to the template film duringthe coating application portion of the spin cycle, to produce abackfilled sample.

The sample was removed from spin coater and placed on a hotplate at 50°C. for 30 minutes, covered with an aluminum tray. The sample was thenallowed to cool to room temperature. The sample was laminated at 70° F.(21.1° C.), coating side down, to a piece of polyester using a thermalfilm laminator (GBC Catena 35, GBC Document Finishing, Lincolnshire,Ill.).

Vinyl silsesquioxane was prepared as disclosed in Example 9.

The template film was removed, leaving a structured film on unprimedPET. A piece of the structured film slightly larger than 5.1 cm×7.6 cm(2 inch×3 inch) was adhered to a 1 mm thick 5.1 cm×7.6 cm (2 inch×3inch) glass microscope slide (available from VWR International, RadnorPa.) with tape, structure side up. The glass slide and sample were thenput on a Model WS-6505-6npp/lite spin coater (available from LaurellTechnologies Corporation, North Wales Pa.) directly on the vacuum chuck.A vacuum of 64 kPa (19 inches of Hg) was applied to hold the sample tothe chuck. The spin coater was programmed for 500 RPM for 5 seconds(coating application step) then 1000 RPM for 15 sec (spin step), then1000 RPM for 20 seconds (dry step). Approximately 1-2 mL of the vinylSSQ radiation curable system was applied to the template film during thecoating application portion of the spin cycle, to produce a backfilledsample.

The sample was removed from spin coater and placed on a hotplate at 50°C. for 30 minutes, covered with an aluminum tray. The sample was thenallowed to cool to room temperature. The sample was laminated at 230° F.(110° C.), coating side down, to a 1 mm thick 5.1 cm×7.6 cm (2 inch×3inch) glass microscope slide (available from VWR International, RadnorPa.) using a thermal film laminator (GBC Catena 35, GBC DocumentFinishing, Lincolnshire, Ill.). The laminated sample was allowed cool toroom temperature.

The sample was then cured in a belt fed cure chamber (RPC industries)fitted with a Fusion H bulb in nitrogen (1 pass, 25 fpm). The sample wasremoved from the chamber, and cooled to room temperature. The unprimedPET was then removed from the sample. This process produced a samplewith embedded nanostructure, and a smooth top. The uncured areas wereallowed to reflow for 1-5 minutes at room temperature. The sample wasthen cured in a belt fed cure chamber (RPC industries) fitted with aFusion H bulb in nitrogen (1 pass, 25 fpm). The sample was removed fromthe chamber, and cooled to room temperature. This process produced apatterned, nanostructured sample where the unstructured areas retainedmaterial but did not retain structure.

Example 14 High Index Backfill on Top of Vinyl Silsesquioxane

A piece of the template film slightly larger than 5.1 cm×7.6 cm (2inch×3 inch) was adhered to a 1 mm thick 5.1 cm×7.6 cm (2 inch×3 inch)glass microscope slide (available from VWR International, Radnor Pa.)with tape. The glass slide and sample were then put on a ModelWS-6505-6npp/lite spin coater (available from Laurell TechnologiesCorporation, North Wales Pa.) directly on the vacuum chuck. A vacuum of64 kPa (19 inches of Hg) was applied to hold the sample to the chuck.The spin coater was programmed for 500 RPM for 5 seconds (coatingapplication step) then 1000 RPM for 15 sec (spin step), then 1000 RPMfor 20 seconds (dry step). Approximately 1-2 milliliters of the opticalcoupling material was applied to the template film during the coatingapplication portion of the spin cycle, to produce a backfilled sample.

The sample was removed from spin coater and placed on a hotplate at 50°C. for 30 minutes, covered with an aluminum tray. laminated at 230° F.(110° C.), coating side down, to a film of PET using a thermal filmlaminator (GBC Catena 35, GBC Document Finishing, Lincolnshire, Ill.).The laminated sample was allowed cool to room temperature. The laminatedsample was then cured under UV lights with a UV processor (2 passes).The template film was then removed from the sample, leaving a curedlayer on the PET.

The PET sample was adhered to a 1 mm thick 5.1 cm×7.6 cm (2 inch×3 inch)glass microscope slide (available from VWR International, Radnor Pa.)with tape. The glass slide and sample were then put on a ModelWS-6505-6npp/lite spin coater (available from Laurell TechnologiesCorporation, North Wales Pa.) directly on the vacuum chuck. A vacuum of64 kPa (19 inches of Hg) was applied to hold the sample to the chuck.The spin coater was programmed for 500 RPM for 5 seconds (coatingapplication step) then 1000 RPM for 15 sec (spin step), then 1000 RPMfor 20 seconds (dry step). Approximately 1-2 milliliters of the vinylSSQ radiation curable system was applied to the template film during thecoating application portion of the spin cycle, to a low index adhesionlayer. The sample was removed from spin coater and placed on a hotplateat 50° C. for 30 minutes, covered with an aluminum tray. laminated at230° F. (110° C.), coating side down, to a 1 mm thick 5.1 cm×7.6 cm (2inch×3 inch) glass microscope slide (available from VWR International,Radnor Pa.) using a thermal film laminator (GBC Catena 35, GBC DocumentFinishing, Lincolnshire, Ill.). The laminated sample was allowed cool toroom temperature. The laminated sample was then cured under UV. Thetemplate film was then removed from the sample, leaving a cured layer onthe glass.

Following are a list of embodiments of the present disclosure.

Item 1 is a transfer tape comprising a carrier, a template layer havinga first surface applied to the carrier and having a second surfaceopposite the first surface, wherein the second surface comprises anon-planar structured surface, a release coating disposed upon thenon-planar structured surface of the template layer, and a backfilllayer disposed upon and conforming to the non-planar structured surfaceof the release coating, wherein the template layer is capable of beingremoved from the backfill layer while leaving at least a portion of thestructured surface of the backfill layer substantially intact.

Item 2 is the transfer tape of item 1 further comprising a release linerdisposed upon the backfill layer.

Item 3 is the transfer tape of item 1, wherein the carrier comprises atransparent polymer.

Item 4 is the transfer tape of item 1, wherein the template layercomprises a photocurable organic resin.

Item 5 is the transfer tape of item 1, wherein the release coatingcomprises a chemically vapor deposited tetramethylsilane polymer.

Item 6 is the transfer tape of item 1, wherein the backfill layer is aplanarizing layer.

Item 7 is the transfer tape of item 1, wherein the backfill layercomprises a bilayer of two different materials.

Item 8 is the transfer tape of item 7, wherein one of the bilayerscomprises an adhesion promotion layer.

Item 9 is the transfer tape of item 1, wherein the backfill layercomprises a silsesquioxane.

Item 10 is the transfer tape of item 9, wherein the silsesquioxanecomprises polyvinyl silsesquioxane.

Item 11 is an article comprising a transfer tape according to item 1,and a receptor substrate adjacent to the backfill layer.

Item 12 is the article of item 11, wherein the receptor substratecomprises flexible glass.

Item 13 is the article of item 11, wherein the backfill layer comprisestwo or more materials.

Item 14 is the article of item 13, wherein one of the two or morematerials is an adhesion promotion layer.

Item 15 is the article of item 14, wherein the adhesion promotion layeris patterned.

Item 16 is the article of item 11, wherein the backfill layer iscrosslinked.

Item 17 is the article of item 11, wherein the backfill layer comprisesa structured uncured pattern and a structured crosslinked pattern.

Item 18 is the article of item 17, wherein when the release coatingdisposed upon the structured side of the template layer and the backfilllayer disposed upon the release coating are separated from the transfertape, the structured uncured pattern reflows and is substantiallyunstructured.

Item 19 is the article of item 14, wherein the backfill layer is fullycured.

Item 20 is a transfer tape comprising a carrier, a template layer havinga first surface applied to the carrier and having a second surfaceopposite the first surface, wherein the second surface comprises anon-planar structured surface, and a patterned cured backfill layerdisposed upon the non-planar structured surface.

Item 21 is the transfer tape of item 20 further comprising a releaselayer disposed upon the backfill layer

Item 22 is the transfer tape of item 20 further comprising a crosslinkedunstructured layer in contact with the patterned cured backfill layerand also in contact with the portion of the template layer not coveredby the patterned cured backfill layer.

Item 23 is a transfer tape comprising a carrier, a template layer havinga first surface applied to the carrier and having a second surfaceopposite the first surface, wherein the second surface comprises anon-planar structured surface, an unpatterned cured sacrificial backfilllayer disposed upon the non-planar structured surface, and a receptorsubstrate having an interface with the backfill layer, wherein there arebonding regions and non-bonding regions at the interface of the backfilllayer and the receptor substrate.

All references and publications cited herein are expressly incorporatedherein by reference in their entirety into this disclosure, except tothe extent they may directly contradict this disclosure. Althoughspecific embodiments have been illustrated and disclosed herein, it willbe appreciated by those of ordinary skill in the art that a variety ofalternate and/or equivalent implementations can be substituted for thespecific embodiments shown and disclosed without departing from thescope of the present disclosure. This application is intended to coverany adaptations or variations of the specific embodiments discussedherein. Therefore, it is intended that this disclosure be limited onlyby the claims and the equivalents thereof.

What is claimed is:
 1. An OLED device comprising: a first layer; abackfill layer having a structured first side and a second side; aplanarization layer having a structured first side and a second side;and a second layer; wherein the second side of the backfill layer iscoincident with and adjacent to the first layer, the second side of theplanarization layer is coincident with and adjacent to the second layer,the structured first side of the backfill layer and structured firstside of the planarization layer form a structured interface, therefractive index of the backfill layer is index matched to the firstlayer, and the refractive index of the planarization layer is indexmatched to the second layer.
 2. The OLED device of claim 1, wherein thebackfill layer comprises a nanoparticle composite.
 3. The OLED device ofclaim 1, wherein the backfill layer is made from a polymerizablecomposition comprising monomers cured using actinic radiation.
 4. TheOLED device of claim 1, wherein the backfill layer comprises asilsesquioxane.
 5. The OLED device of claim 1, wherein the backfilllayer comprises nanoparticles.
 6. The OLED device of claim 1, whereinthe backfill layer comprises an acrylic coating including silicananoparticles.
 7. The OLED device of claim 1, wherein the backfill layercomprises an acrylic coating including zirconia nanoparticles.
 8. TheOLED device of claim 1, wherein the planarization layer comprisesnanoparticles.
 9. The OLED device of claim 1, wherein the planarizationlayer comprises an acrylic coating including silica nanoparticles. 10.The OLED device of claim 1, wherein the planarization layer comprises anacrylic coating including zirconia nanoparticles.
 11. The OLED device ofclaim 1, wherein the structures of the backfill layer and planarizationlayer are nanostructures.
 12. The OLED device of claim 1, wherein thebackfill layer comprises a bilayer of two different materials.
 13. TheOLED device of claim 12, wherein one of the bilayers comprises anadhesion promotion layer.
 14. The OLED device of claim 1, wherein thefirst layer is an active matrix OLED backplane.
 15. The OLED device ofclaim 1, wherein the first layer is an active matrix OLED color filterson array.
 16. The OLED device of claim 1, wherein the first layer is anOLED solid state lighting element.
 17. The OLED device of claim 1,wherein the second layer is an active matrix OLED backplane.
 18. TheOLED device of claim 1, wherein the second layer is an active matrixOLED color filters on array.
 19. The OLED device of claim 1, wherein thesecond layer is an OLED solid state lighting element.